dr hab. Przemysław Ranachowski

Zakład Mechaniki Doświadczalnej (ZMD)
Pracownia Wytrzymałości Materiałów (PWM)
stanowisko: adiunkt
telefon: (+48) 22 826 12 81 wew.: 254
pokój: 533
e-mail: pranach

Doktorat
2001Wykorzystanie metody emisji akustycznej do badania dynamiki przemian polimorficznych związków nieorganicznych 
promotor -- prof. dr hab. inż. Ignacy Malecki, IPPT PAN
558 
Habilitacja
2013-06-27Procesy starzeniowe w ceramice elektrotechnicznej 
Ostatnie publikacje
1.Łazarska M., Woźniak T.Z., Ranachowski Z., Ranachowski P., Trafarski A., The application of acoustic emission and artificial neural networks in an analysis of kinetics in the phase transformation of tool steel during austempering, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.1515/amm-2017-0089, Vol.62, No.2, pp.603-609, 2017

Streszczenie:

During the course of the study it involved tool steel C105U was used. The steel was austempered at temperatures of 130°C, 160°C and 180°C respectively. Methods of acoustic emission (AE) were used to investigate the resulting effects associated with transformations and a large number of AE events were registered. Neural networks were applied to analyse these phenomena. In the tested signal, three groups of events were identified of: high, medium and low energy. The average spectral characteristics enabled the power of the signal spectrum to be determined. After completing the process, the results were compiled in the form of diagrams of the relationship of the AE incidence frequency as a function of time. Based on the results, it was found that in the austempering of tool steel, in the first stage of transformation midrib morphology is formed. Midrib is a twinned thin plate martensite. In the 2nd stage of transformation, the intensity of the generation of medium energy events indicates the occurrence of bainite initialised by martensite. The obtained graphic of AE characteristics of tool steel austempering allow conclusions to be drawn about the kinetics and the mechanism of this transformation.

Słowa kluczowe:

carbon steel, austempering, lower bainite, acoustic emission (AE), neural networks

Afiliacje autorów:

Łazarska M.-other affiliation
Woźniak T.Z.-other affiliation
Ranachowski Z.-IPPT PAN
Ranachowski P.-IPPT PAN
Trafarski A.-other affiliation
30p.
2.Żołek N., Ranachowski Z., Ranachowski P., Jóźwiak-Niedźwiedzka D., Kúdela Jr. S., Dvorak T., Statistical assessment of the microstructure of barite aggregate from different deposits using x-ray microtomography and optical microscopy, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.1515/amm-2017-0104, Vol.62, No.2, pp.697-702, 2017

Streszczenie:

Two different barite ore (barium sulfate BaSO4) specimens from different localizations were tested and described in this paper. Analysis of the microstructure was performed on polished sections, and on thin sections using X-ray microtomography (micro-CT), and optical microscopy (MO). Microtomography allowed obtaining three-dimensional images of the barite aggregate specimens. In the tomograms, the spatial distribution of the other polluting phases, empty space as well as cracks, pores, and voids – that exceeded ten micrometers of diameter-were possible to visualize. Also, the micro-CT allowed distinguishing between minerals of different density, like SiO2 and BaSO4. Images obtained and analyzed on thin sections with various methods using the optical microscopy in transmitted light delivered additional information on the aggregate microstructure, i.e. allow for estimation of the different kinds of inclusions (like the different density of the minerals) in the investigated specimens. Above methods, which were used in the tests, completed each another in order to supply a set of information on inclusions’ distribution and to present the important differences of the barite aggregate specimens microstructure.

Słowa kluczowe:

barite ore, barite aggregate, microstructure, optical microscopy, thin sections analysis, X-ray tomography

Afiliacje autorów:

Żołek N.-IPPT PAN
Ranachowski Z.-IPPT PAN
Ranachowski P.-IPPT PAN
Jóźwiak-Niedźwiedzka D.-IPPT PAN
Kúdela Jr. S.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
Dvorak T.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
30p.
3.Mackiewicz M., Mikulski J.L., Wańkowicz J., Kucharski S., Ranachowski P., Ranachowski Z., Study of composite insulator sheds subjected to wheel test, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.1515/amm-2017-0101, Vol.62, No.2, pp.679-686, 2017

Streszczenie:

The paper presents investigation of the properties of the surface and the material stiffness – flexibility of series of samples taken from the sheds of the composite insulators. The insulators were previously subjected to wheel test. The wheel test and 1000 h salt fog test are regarded as alternative examination of the material resistance to the effects of electrical surface discharges. There were investigated two series of the samples of the composite insulators sheds. Examined specimens, made of HTV silicone rubber, were taken from the sheds of medium-voltage composite insulators of two different manufacturers. Insulators of both types passed the 1000 h salt fog test without reservation. Meanwhile, the wheel test can provide a basis for better distinguishing between physical properties of the tested materials. In the case of the insulators of one of the manufacturers the wheel test result was negative. Cross puncture effect of the sheds took place in several places. In addition, sheds were covered with dark coating of varying thicknesses. The results of the study indicated a significantly stronger influence of electrical and temperature factors on the sheds under investigations during the wheel test than in the case of the 1000 h salt fog test. It can be stated that these tests cannot be considered as alternative and it seems that wheel test enables better distinguishing between properties of the materials.

Słowa kluczowe:

composite insulators, silicone rubber, wheel test, electrical surface discharges, tracking and erosion

Afiliacje autorów:

Mackiewicz M.-other affiliation
Mikulski J.L.-other affiliation
Wańkowicz J.-other affiliation
Kucharski S.-IPPT PAN
Ranachowski P.-IPPT PAN
Ranachowski Z.-IPPT PAN
30p.
4.Kúdela Jr. S., Švec P., Bajana O., Orovčík L., Ranachowski P., Ranachowski Z., Saffil alumina fibers reinforced dual-phase Mg-Li and Mg-Li-Zn alloys, KOVOVE MATERIALY-METALLIC MATERIALS, ISSN: 0023-432X, DOI: 10.4149/km 2017 3 195, Vol.55, pp.195-203, 2017

Streszczenie:

The gas pressure infiltration technique was used to prepare Saffil alumina fibers reinforced Mg-Li and Mg-Li-Zn matrix composites with a dual-phase matrix structure. There was investigated the effect of variable Li content (6.2–10.3 wt.% Li) and Zn alloying (∼ 1.5 wt.% Zn) on the proof stress Rp0.2 of prepared composites. Rp0.2 values increased monotonously with rising fraction of Saffil fibers (5, 10 and 15 vol.%) reaching the maximum of about 250 MPa for Mg-Li matrix composites. Rp0.2 values of Mg-Li-Zn matrix composites were lower. Strengthening effect of Saffil fibers was promoted by the displacement redox reaction with Mg-Li and Mg-Li-Zn melts in which only Li significantly participated. Zn alloying retarded the displacement redox reaction. Too extensive reaction, however, resulted in the fiber damage and the drop in composite strength.

Słowa kluczowe:

Mg-Li alloys, Saffil fibers, metal matrix composites, short-fiber strengthening, reactive wetting, displacement reactions

Afiliacje autorów:

Kúdela Jr. S.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
Švec P.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
Bajana O.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
Orovčík L.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
Ranachowski P.-IPPT PAN
Ranachowski Z.-IPPT PAN
20p.
5.Pawełek A., Ozgowicz W., Ranachowski Z., Kúdela S., Piątkowski A., Kúdela S.Jr., Ranachowski P., Behaviour of Acoustic Emission in Deformation and Microcracking Processes of Mg Alloys Matrix Composites Subjected to Compression Tests, ARCHIVES OF CURRENT RESEARCH INTERNATIONAL, ISSN: 2454-7077, DOI: 10.9734/ACRI/2017/34598, Vol.8, No.2, pp.1-13, 2017

Streszczenie:

Research results on both mechanical and acoustic emission (AE) behavior of Mg-Li and Mg-Al alloys matrix composites (AMC) reinforced with ceramic δ-Al2O3 or carbon fibers subjected to the channel-die compression at room and elevated temperatures are presented in this paper. The AE measurements at room temperature showed that, the effect of anisotropy of the fibres distribution (random planar distribution) with respect to the compression axis appeared in the most investigated composites, whereas the AE activity at 140°C revealed a two- range character and the rate of AE events at 140°C was higher than at room temperature. These effects are discussed in terms of both the differences in thermal expansion between the fibres and the matrix as well as the weakening of the coherency between the fibres and the matrix leading to stronger debonding effects at 140°C than at room temperature. The spectral analysis of AE signals was performed with the Windowed Fourier Transform method, which served to plot the spectral density of AE signal as a function of frequency. The alominous and corundum ceramics types were also investigated in order to illustrate the enhanced AE, which was related to the different crack paths in the final stages of the sample degradation. The results were also discussed on the basis of SEM images, including the in-situ observations of microcracking as well as the dislocation strain mechanisms and microcracking ones during the channel-die compression of the Mg-Li-Al AMC.

Słowa kluczowe:

composites, fibres microcracking, acoustic emission, strain mechanisms, dislocations

Afiliacje autorów:

Pawełek A.-other affiliation
Ozgowicz W.-other affiliation
Ranachowski Z.-IPPT PAN
Kúdela S.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
Piątkowski A.-Institute of Metallurgy and Materials Science, Polish Academy of Sciences (PL)
Kúdela S.Jr.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
Ranachowski P.-IPPT PAN
6.Ranachowski P., Ranachowski Z., Jaroszewski M., Wieczorek K., Kúdela Jr. S., Mechanoacoustic Research Method of Degradation Processes in Electroceramics Materials, IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION, ISSN: 1070-9878, DOI: 10.1109/TDEI.2015.005568, Vol.23, No.3, pp.1251-1259, 2016

Streszczenie:

The paper presents the concept of mechanoacoustic testing of degradation processes of ceramic materials, which is applied to diagnose high voltage insulators in operation. The method depends on the application of slowly increasing compressive loading acting on the sample, with simultaneous recording of acoustic emission (AE) descriptors. The process of loading is continued to the destruction or stopped at different stresses, and the samples are subjected to microscopic examination. Microscopic analysis of the samples enables determining the effects of stress action. The results were compared with the images of similar materials obtained from the insulators after different periods of operation. On this basis, there were distinguished consecutive stages of ageing of electrotechnical porcelain materials and corresponding effects of their structure degradation. Using slowly increasing quasi-static compressive loading in a relatively short-term mechanoacoustic test makes it possible to get results similar to those of long lasting degradation effects in operated electroinsulating objects. Using this method there is possible to describe the factors which affect short and long-term mechanical strength of the tested materials. There is also possible assessment of the validity and application of the theories explaining the strength of porcelains. There was presented research of the influence of the mullite phase on the short- and long-term mechanical strength of electrotechnical porcelain of different types.

Słowa kluczowe:

Degradation, Stress, Insulators, Porcelain, Aging, Microscopy

Afiliacje autorów:

Ranachowski P.-IPPT PAN
Ranachowski Z.-IPPT PAN
Jaroszewski M.-other affiliation
Wieczorek K.-other affiliation
Kúdela Jr. S.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
30p.
7.Kúdela Jr. S., Švec P., Bajana O., Orovčík L., Ranachowski P., Ranachowski Z., Strengthening in dual-phase structured Mg-Li-Zn alloys, KOVOVE MATERIALY-METALLIC MATERIALS, ISSN: 0023-432X, DOI: 10.4149/km_2016_6_483, Vol.54, pp.483-489, 2016

Streszczenie:

Proof stress Rp0.2 of dual-phase α + β structured Mg-Li and Mg-Li-Zn alloys has been inspected in terms of the strengthening contributions of α- and β-phases. The alloys studied with a variable fraction of α- and β-phases have been subjected to compression straining tests, microhardness measurements and structural analysis by EDX and XRD. Alloying with 1.5 wt.% Zn results in the hardening of both α- and β-phases which however exhibit different hardening responses due to different Zn enrichment. The rule of the mixture has been used to interpret Rp0.2 values by taking into account the fraction of α- and β-phases and their strength level represented by their microhardness. Compression stress-strain curves indicate that work hardening of alloys studied depends considerably on the fraction of α-phase and is higher for Zn-containing alloys.

Słowa kluczowe:

Mg-Li, Mg-Li-Zn, dual-phase alloy, solution hardening, ageing, work hardening

Afiliacje autorów:

Kúdela Jr. S.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
Švec P.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
Bajana O.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
Orovčík L.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
Ranachowski P.-IPPT PAN
Ranachowski Z.-IPPT PAN
20p.
8.Papliński P., Ranachowski P., Mikrostruktura i stopień degradacji warystorów ZnO z eksploatacji w badaniach mikroskopowych, PRZEGLĄD ELEKTROTECHNICZNY, ISSN: 0033-2097, DOI: 10.15199/48.2016.10.29, Vol.92, No.10, pp.120-125, 2016

Streszczenie:

W artykule przedstawiono wyniki badań mikrostruktury warystorów ZnO, wchodzących w skład beziskiernikowych ograniczników przepięć wysokiego napięcia. Badania obejmowały warystory wykonane w różnych okresach i przez różnych producentów. Inspiracją do podjęcia badań były różniące się charakterystyki prądów płynących przez ograniczniki w funkcji napięcia systemu w rozdzielni 400 kV oraz temperatury, w cyklu rocznym. Ponadto badane były efekty degradacji mikrostruktury warystorów po awarii rozszczelnionego ogranicznika przepięć. Uzyskane wyniki dały podstawę do oceny parametrów mikrostruktury warystorów ZnO z punktu widzenia ich trwałości i odporności na procesy degradacji.

Słowa kluczowe:

ogranicznik przepięć, warystor ZnO, mikrostruktura ceramiki, degradacja ceramiki

Afiliacje autorów:

Papliński P.-other affiliation
Ranachowski P.-IPPT PAN
14p.
9.Pawełek A., Piątkowski A., Wajda W., Skuza W., Tarasek A., Ranachowski Z., Ranachowski P., Ozgowicz W., Kúdela Jr. S., Kúdela S., Plastic instabilities induced by the Portevin - Le Châtelier effect and fracture character of deformed Mg-Li alloys investigated using the acoustic emission method, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.1515/amm-2016-0152, Vol.61, No.2, pp.897-904, 2016

Streszczenie:

The results of the investigation of both mechanical and acoustic emission (AE) behaviors of Mg4Li5Al and Mg4Li4Zn alloys subjected to compression and tensile tests at room temperature are compared with the test results obtained using the same alloys and loading scheme but at elevated temperatures. The main aim of the paper is to investigate, to determine and to explain the relation between plastic flow instabilities and the fracture characteristics. There are discussed the possible influence of the factors related with enhanced internal stresses such as: segregation of precipitates along grain boundaries, interaction of solute atoms with mobile dislocations (Cottrell atmospheres) as well as dislocation pile-ups which may lead to the microcracks formation due to the creation of very high stress concentration at grain boundaries. The results show that the plastic flow discontinuities are related to the Portevin-Le Châtelier phenomenon (PL effect) and they are correlated with the generation of characteristic AE pulse trains. The fractography of broken samples was analyzed on the basis of light (optical), TEM and SEM images.

Słowa kluczowe:

lightweight alloys, Acoustic Emission, fracture, Portevin-Le Châtelier phenomenon, twinning, dislocations, shear bands

Afiliacje autorów:

Pawełek A.-other affiliation
Piątkowski A.-Institute of Metallurgy and Materials Science, Polish Academy of Sciences (PL)
Wajda W.-other affiliation
Skuza W.-other affiliation
Tarasek A.-other affiliation
Ranachowski Z.-IPPT PAN
Ranachowski P.-IPPT PAN
Ozgowicz W.-other affiliation
Kúdela Jr. S.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
Kúdela S.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
10.Ranachowski P., Ranachowski Z., Kúdela Jr. S., Pawełek A., Piątkowski A., Study of factors determinant of siliceous electrical porcelain resistance to structural degradation, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.1515/amm-2016-0244, Vol.61, No.3, pp.1143-1150, 2016

Streszczenie:

The subject of this study was investigation of the factors that have a decisive influence on the resistance of siliceous porcelain to degradation processes. There was tested material C 110 type, which is widely used for the production of low-voltage (LV) elements such as insulators and bushings. On the basis of mechanical-acoustic and microscopic research of small-sized samples, which were subjected to compression, there were distinguished successive stages of degradation of the material structure. In the authors’ opinion, they have a reference to the ageing process, taking place during many years of work under operating conditions. Thus, it was possible to assess the structural factors that determine the durability and reliability of LV electroinsulating elements. The results were related to electrical aluminous porcelains.

Słowa kluczowe:

porcelain insulating materials, ageing processes, acoustic emission (AE), optical microscopy

Afiliacje autorów:

Ranachowski P.-IPPT PAN
Ranachowski Z.-IPPT PAN
Kúdela Jr. S.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
Pawełek A.-other affiliation
Piątkowski A.-Institute of Metallurgy and Materials Science, Polish Academy of Sciences (PL)
11.Ranachowski Z., Jóźwiak-Niedźwiedzka D., Ranachowski P., Dąbrowski M., Kúdela Jr. S., Dvorak T., The determination of diffusive tortuosity in concrete specimens using X-ray microtomography, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.1515/amm-2015-0140, Vol.60, No.2, pp.1115-1119, 2015

Streszczenie:

The paper presents a method of pore connectivity analysis applied to specimens of cement based composites differing in water to cement ratio. The method employed X-ray microtomography (micro-CT). Microtomography supplied digitized three-dimensional radiographs of small concrete specimens. The data derived from the radiographs were applied as an input into the application based on the algorithm called ‘random walk simulation’. As the result a parameter called diffusive tortuosity was established and compared with estimated porosity of examined specimens.

Artykuł prezentuje metodę wyznaczania parametru charakteryzującego intensywność połączeń mikroporów w zastosowaniu do próbek kompozytów z matrycą cementową, różniących się stosunkiem wodnocementowym. Metoda bazuje na wynikach badań z zastosowaniem mikrotomografii rentgenowskiej. Analizowano zdigitizowane zestawy danych, opisujące trójwymiarową reprezentację mikrostruktury niewielkich próbek wykonanych z betonu. Przygotowane w ten sposób skany mikrostruktury zastosowano jako dane wejściowe wprowadzone do oprogramowania wykorzystujacego algorytm ‘przypadkowo migrujących cząstek wirtualnych’. W ten sposób wyznaczono parametr mikrostruktury znany jako krętość dyfuzyjna. Parametr ten porównano z porowatością obserwowaną wyznaczoną dla zbadanych próbek przy wykorzystaniu analizy jasności voxeli w analizowanych próbkach.

Słowa kluczowe:

X-ray tomography, concrete microstructure, diffusive tortuosity

Afiliacje autorów:

Ranachowski Z.-IPPT PAN
Jóźwiak-Niedźwiedzka D.-IPPT PAN
Ranachowski P.-IPPT PAN
Dąbrowski M.-IPPT PAN
Kúdela Jr. S.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
Dvorak T.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
30p.
12.Ranachowski Z., Jóźwiak-Niedźwiedzka D., Ranachowski P., Rejmund F., Dąbrowski M., Kúdela Jr. S., Dvorak T., Application of X-ray microtomography and optical microscopy to determine the microstructure of concrete penetrated by carbon dioxide, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.2478/amm-2014-0245, Vol.59, No.4, pp.1451-1457, 2014

Streszczenie:

In the paper two advanced methods for testing cement based composites are described and compared. These are X-ray microtomography and optical microscopy. Microtomography supplies three-dimensional images of small concrete specimens. In the tomograms all cracks, pores and other voids and inclusions, that exceed a few micrometers, are shown. Such visualisation can become a valuable tool for analysis of the basic material properties. Images obtained on thin sections and analysed with various methods on optical microscopes supply additional information on material microstructure that cannot be obtained in tomograms. For example it is relatively easy to determine zone penetrated by CO2 ingress. These two methods, presented on examples of tests, complete each another in order to supply a set of information on composition and defects of tested composite materials.

Słowa kluczowe:

cement matrix composites, concrete deterioration, X-ray tomography, microscopic analysis, concrete microstructure

Afiliacje autorów:

Ranachowski Z.-IPPT PAN
Jóźwiak-Niedźwiedzka D.-IPPT PAN
Ranachowski P.-IPPT PAN
Rejmund F.-IPPT PAN
Dąbrowski M.-IPPT PAN
Kúdela Jr. S.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
Dvorak T.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
25p.
13.Woźniak T.Z., Ranachowski Z., Ranachowski P., Ozgowicz W., Trafarski A., The application of neural networks for studying phase transformation by the method of acoustic emission in bearing steel, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.2478/amm-2014-0288, Vol.59, No.4, pp.1705-1712, 2014

Streszczenie:

The research was carried out on steel 100CrMnSi6-4 under isothermal austempering resulting in forming the duplex structure: martensitic and bainitic. The kinetics of transformation was controlled by the acoustic emission method. Complex phase transformations caused by segregation and carbide banding occur at the low-temperature heat treatment of bearing steel. At the temperature close to MS, a certain temperature range occurs where an effect of the first product of prior athermal martensite on the bainitic transformation can be observed. In the registered signal about 15 million various events were registered. There were considered three types of acoustic emission events (of high, medium and low energy), with relatively wide sections and with different spectral characteristics. It was found that the method of acoustic emission complemented by the application of neural networks is a sensitive tool to identify the kinetics of bainitic transformation and to show the interaction between martensitic and bainitic transformations.

Słowa kluczowe:

Bearing steel, austempering, lower bainite, acoustic emission, neural networks

Afiliacje autorów:

Woźniak T.Z.-other affiliation
Ranachowski Z.-IPPT PAN
Ranachowski P.-IPPT PAN
Ozgowicz W.-other affiliation
Trafarski A.-other affiliation
25p.
14.Kúdela Jr. S., Iždinský K., Oswald S., Ranachowski P., Ranachowski Z., Kúdela S., Decomposition of silica binder during infiltration of Saffil fiber preform with Mg and Mg-Li melts, KOVOVE MATERIALY-METALLIC MATERIALS, ISSN: 0023-432X, Vol.52, No.4, pp.183-188, 2014

Streszczenie:

Mg and Mg-Li matrix composites were prepared by the melt infiltration of fibrous preform consisting of Saffil alumina fibers and the silica binder. During this process there has occurred decomposition of silica binder and/or surface silica film by displacement redox reactions and the reaction products were characterized using SEM, TEM, SAED, FTIR and XPS techniques. The only reaction products found in Mg infiltrated Saffil preform were MgO and Mg2Si. In Mg-Li melt infiltrated Saffil preform there was found besides MgO and Mg 2 Si also the non- crystalline phase that appears to be the lithium silicate xLi2O ySiO2. Binary lithium silicides and ternary magnesium-lithium silicides were not detected

Słowa kluczowe:

Mg-Li composites, Saffil fibers, silica binder, melt infiltration, XPS, FTI

Afiliacje autorów:

Kúdela Jr. S.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
Iždinský K.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
Oswald S.-Institute for Complex Materials (DE)
Ranachowski P.-IPPT PAN
Ranachowski Z.-IPPT PAN
Kúdela S.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
20p.
15.Ranachowski P., Rejmund F., Ranachowski Z., Pawełek A., Piątkowski A., Kúdela Jr. S., Influence of microstructure on the properties of siliceous electrical porcelain, PRZEGLĄD ELEKTROTECHNICZNY, ISSN: 0033-2097, DOI: 10.12915/pe.2014.10.28, Vol.90, No.10, pp.110-113, 2014

Streszczenie:

The paper presents the microscopic and mechanoacoustic study of degradation processes of the porcelain material C 110 type. Small-sized samples, derived from the low voltage insulator, were subjected to a slow, quasi-static compression, with simultaneous recording of acoustic emission descriptors. There were distinguished consecutive stages of the material degradation. Obtained results were compared with the images of the microstructure of low-voltage insulator materials after many years of operation. On this basis, there were distinguished the factors determinant of the short-term strength of porcelain and its resistance to ageing processes under operating conditions.

Słowa kluczowe:

electrical porcelain, microscopic analysis, acoustic emission, degradation of the porcelain

Afiliacje autorów:

Ranachowski P.-IPPT PAN
Rejmund F.-IPPT PAN
Ranachowski Z.-IPPT PAN
Pawełek A.-other affiliation
Piątkowski A.-Institute of Metallurgy and Materials Science, Polish Academy of Sciences (PL)
Kúdela Jr. S.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
10p.
16.Ranachowski P., Rejmund F., Ranachowski Z., Pawełek A., Piątkowski A., Kúdela Jr. S., Evaluation of the mullite hypothesis in respect of electrotechnical porcelains, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.2478/amm-2013-0158, Vol.58, No.4, pp.1177-1181, 2013

Streszczenie:

The paper presents the evaluation of the mullite hypothesis explaining the strength of porcelains. There was researched the influence of the mullite phase on the short- and long-term mechanical strength of electrotechnical porcelain of different types (C 110, C 112, C 120 and C 130). The total mullite phase content, the size and distribution of precipitates and dispersed single crystals in the glassy matrix were considered. Mechanoacoustic and microscopic techniques as well as ultrasonic testing were used during the investigation. The role of the mullite phase in the increase of strength and resistance to aging processes of electrical porcelain of various types was described. Mullite hypothesis is valid in reference to siliceous (C 110), cristobalite (C 112) and aluminous C 120 type materials of a typical raw components content and phase composition. In the case of modern strengthened C 120 and C 130 type aluminous materials advantageous are only dispersed fine mullite needles. The precipitates of mullite phase, especially of bigger size, are undesirable.

Słowa kluczowe:

electrotechnical porcelain, porcelain degradation, acoustic emission (AE), microscopic analysis

Afiliacje autorów:

Ranachowski P.-IPPT PAN
Rejmund F.-IPPT PAN
Ranachowski Z.-IPPT PAN
Pawełek A.-other affiliation
Piątkowski A.-Institute of Metallurgy and Materials Science, Polish Academy of Sciences (PL)
Kúdela Jr. S.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
20p.
17.Ranachowski P., Rejmund F., Etienne J., In Memoriam A Look at the Life and Activity of a Prominent Polish Acoustician of the 20th Century Professor Ignacy MALECKI (1912–2004) on the Occasion of the Centenary Anniversary of His Birth, ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, DOI: 10.2478/aoa-2013-0001, Vol.38, No.1, pp.3-12, 2013

Streszczenie:

Ignacy Malecki was born on November 18, 1912, at the family estate of Pokiewnia near Vilnius. After Poland regained its independence in 1918, the town was at the border of the Second Republic of Poland and Central Lithuania. The church and village were located in the Polish area, while the family estate on the Lithuanian side. It took some time before those parts could be reunited.
....

Afiliacje autorów:

Ranachowski P.-IPPT PAN
Rejmund F.-IPPT PAN
Etienne J.-IPPT PAN
20p.
18.Papliński P., Ranachowski P., Badania powierzchni elementów wewnętrznych ograniczników przepięć, PRZEGLĄD ELEKTROTECHNICZNY, ISSN: 0033-2097, Vol.R. 88, No.5a, pp.73-76, 2012

Streszczenie:

W artykule przedstawiono wyniki badań powierzchni nieuszkodzonych i uszkodzonych podczas eksploatacji elementów wewnętrznych ograniczników przepięć. Elementy te wytypowano na podstawie uprzednio wykonanych charakterystyk prądowych pod napięciem sieciowym. Stwierdzono, że analiza kształtu prądu płynącego przez ogranicznik może być pomocna w ocenie jego stopnia zdegradowania oraz może stanowić podstawę dopuszczenia go do dalszej eksploatacji.

Słowa kluczowe:

ogranicznik przepięć, charakterystyka prądowa, warystor, włókno szklane

Afiliacje autorów:

Papliński P.-other affiliation
Ranachowski P.-IPPT PAN
15p.
19.Ranachowski P., Rejmund F., Ranachowski Z., Pawełek A., Piątkowski A., Kúdela Jr. S., Rola fazy mulitowej w podwyższeniu odporności elektroporcelan na procesy starzeniowe, PRZEGLĄD ELEKTROTECHNICZNY, ISSN: 0033-2097, Vol.88, No.11b, pp.162-165, 2012

Streszczenie:

W pracy przedstawiono badania wpływu fazy mulitowej na krótko- i długotrwałą wytrzymałość mechaniczną elektroporcelan rodzaju C 110, C 112, C 120 oraz C 130. Rozpatrywana była sumaryczna zawartość fazy mulitowej, wielkość i rozłożenie jej wydzieleń oraz niezaglomeryzowanych kryształów w osnowie szklistej. W badaniach wykorzystano metodę mechanoakustyczną, techniki mikroskopowe (MO i SEM) oraz metodę ultradźwiękową. Przedstawiono rolę fazy mulitowej w podwyższeniu odporności na procesy starzeniowe porcelany elektrotechnicznej różnego rodzaju.

Słowa kluczowe:

porcelana elektrotechniczna, degradacja tworzyw porcelanowych, emisja akustyczna, badania mikroskopowe

Afiliacje autorów:

Ranachowski P.-IPPT PAN
Rejmund F.-IPPT PAN
Ranachowski Z.-IPPT PAN
Pawełek A.-other affiliation
Piątkowski A.-Institute of Metallurgy and Materials Science, Polish Academy of Sciences (PL)
Kúdela Jr. S.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
15p.
20.Kúdela S., Pawełek A., Ranachowski Z., Piątkowski A., Kúdela Jr. S., Ranachowski P., Effect of Al alloying on the Hall-Petch strengthening and AE in compressed Mg-Li-Al alloys before and after HPT processing, KOVOVE MATERIALY-METALLIC MATERIALS, ISSN: 0023-432X, DOI: 10.4149/km_2011_4_271, Vol.49, No.4, pp.271-277, 2011

Streszczenie:

The paper deals with the effect of Al content in two-phase Mg-10Li-xAl (x = 0, 1, 5) alloys on their straining behavior before and after severe plastic deformation by high pressure torsion. Both coarse-grained and ultrafine-grained alloys were compression strained in channel-die device with simultaneous acoustic emission monitoring. It has been observed that Hall-Petch strengthening in ultra-fine grained alloys superposes with the strengthening resulting from Al alloying (solution hardening, particulate strengthening). Superposition of these strengthening mechanisms becomes stronger with increase in Al content, presumably due to enhanced grain refining effect.

Słowa kluczowe:

Mg-Li-Al alloys, grain refinement, high pressure torsion, acoustic emission, Hall-Petch strengthening

Afiliacje autorów:

Kúdela S.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
Pawełek A.-other affiliation
Ranachowski Z.-IPPT PAN
Piątkowski A.-Institute of Metallurgy and Materials Science, Polish Academy of Sciences (PL)
Kúdela Jr. S.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
Ranachowski P.-IPPT PAN
20p.
21.Mityurich G.S., Aleksiejuk M., Ranachowski P., Pelivanov I.M., Serdyukov A.N., Photoacoustic diagnostics of inhomogeneous gyrotropic materials with internal stress using bessel light beams, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.2478/v10172-011-0141-6, Vol.56, No.4, pp.1235-1242, 2011

Streszczenie:

This paper considers the investigation of photoacoustic transformation in naturally-gyrotropic and magnetoactive crystals, with internal stress under sound excitation in different modes by Bessel light beams (BLB). In the range of high modulation frequencies (Ω > 1 MHz), the dependence of the photoacoustic response amplitude on the radial coordinate ρ exhibits resonant phenomenon, which can be used to increase the resolution of photoacoustic spectroscopy for media with internal stresses. The expressions for amplitudes of photoacoustic signals in strained crystalline samples were obtained under different boundary conditions, taking into account the dependence of the thermoelastic coupling coefficient on the initial strain in the sample. It was showed that a resonant increase in the amplitude signal is related to the dependence on the geometric parameters of the sample-piezoelectric transducer system, the values of Murnagan constants, the mode composition of the Bessel light beam, and its amplitude modulation frequency.

Słowa kluczowe:

photoacoustic spectroscopy, Bessel light beams, magnetoactive gyrotropic materials

Afiliacje autorów:

Mityurich G.S.-other affiliation
Aleksiejuk M.-IPPT PAN
Ranachowski P.-IPPT PAN
Pelivanov I.M.-other affiliation
Serdyukov A.N.-other affiliation
20p.
22.Ranachowski P., Rejmund F., Ranachowski Z., Pawełek A., Piątkowski A., Mechanoacoustic and microscopic study of aluminous porcelain resistance to structural degradation, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.2478/v10172-011-0140-7, Vol.56, No.4, pp.1227-1233, 2011

Streszczenie:

The paper presents mechanoacoustic and microscopic testing of degradation processes of modern C 120 electrotechnical porcelain of domestic medium voltage line insulator. Samples of small dimensions, cut off from the rod of insulator, were subjected to compressive loading, with recording of acoustic emission descriptors. Microscopic analysis enabled determining the advancement of degradation effects. Three stages of the structure degradation were distinguished. The effectiveness of dispersive and fibrous reinforcement of modern aluminous porcelain C 120 type has been described. Structural strengthening by corundum grains and mullite needle shaped crystals improves mechanical parameters and distinguishes this material from typical aluminosilicate ceramics. The presented results enable drawing up the conclusions concerning the resistance of investigated material to the ageing degradation process development during long term operation.

Słowa kluczowe:

aluminous porcelain, structural degradation, acoustic emission (AE), microscopic analysis

Afiliacje autorów:

Ranachowski P.-IPPT PAN
Rejmund F.-IPPT PAN
Ranachowski Z.-IPPT PAN
Pawełek A.-other affiliation
Piątkowski A.-Institute of Metallurgy and Materials Science, Polish Academy of Sciences (PL)
20p.
23.Ranachowski P., Rejmund F., Ranachowski Z., Pawełek A., Piątkowski A., Aluminous porcelain degradation study using mechanoacoustic and microscopic methods, ARCHIVES OF ELECTRICAL ENGINEERING, ISSN: 0004-0746, DOI: 10.2478/v10171-011-0011-x, Vol.60, No.2, pp.109-128, 2011

Streszczenie:

This experimental paper comprises the results of acoustic emission (AE), microscopic and ultrasonic measurements of samples subjected to slowly increasing compressive stress. On the basis of conducted measurements the successive stages of the material structural degradation have been recognized. The objects of study were samples made of C 120 aluminous porcelain. The investigated material has found at present the application in the fabrication of technical elements like overhead power line insulators. In the case of such objects, not only high mechanical strength, but especially elevated durability as well as operational reliability are required. The expected "life time" of net insulators during exploitation is about 40 years. The analysis of obtained mechanoacoustic dependences pointed out a complex mechanism of degradation of the material. Microscopic investigation of samples, which were stressed to different levels of load, enabled to specify the development of gradual growth of microcracks and successive crushing out of elements of the structure. These processes appear to be similar to the ageing processes occurring in the material during long period of exploitation under a working load. Three stages of the structure degradation were distinguished. The preliminary and subcritical ones show low or moderate intensity of AE signals and considerable variety for the particular samples. The critical stage directly precedes the destructtion of samples. Its range is relatively narrow and reveals the AE activity of high energy. The effectiveness of dispersive and fibrous reinforcement of modern aluminous porcelain C 120 type has been described. Structural strengthening by corundum grains and mullite needle shaped crystals improves mechanical parameters and distinguishes this material from typical aluminosilicate ceramics. The presented results enable drawing up the conclusions concerning the resistance of investigated material to the ageing degradation process development during long term operation.

Słowa kluczowe:

aluminous porcelain, ceramic insulators, insulator testing, acoustic emission, microscopic analysis, structural degradation

Afiliacje autorów:

Ranachowski P.-IPPT PAN
Rejmund F.-IPPT PAN
Ranachowski Z.-IPPT PAN
Pawełek A.-other affiliation
Piątkowski A.-Institute of Metallurgy and Materials Science, Polish Academy of Sciences (PL)
6p.
24.Ranachowski P., Rejmund F., Ranachowski Z., Jaroszewski M., Pospieszna J., Wieczorek K., Acoustic investigations of long-rod insulators and their material properties, IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION, ISSN: 1070-9878, Vol.17, No.1, pp.81-88, 2010

Streszczenie:

The paper presents a nondestructive ultrasonic method of investigating long-rod insulators used on overhead power lines and in substations. A correlation between the degree of degradation of porcelain C 120 and the ultrasonic wave propagation and attenuation parameters was established. The ultrasonic method was used to analyze the quality of groups of line and post insulators after many years of service. Also a new mechanoacoustic method of investigating the stages in the degradation of insulator porcelain was applied. As a result of the investigations carried out on samples of porcelain C 130 the successive stages in the degradation of ceramic insulators during their service life were determined.

Słowa kluczowe:

Ceramic insulators, insulator testing, acoustic measurements, ultrasonic applications, acoustic emission

Afiliacje autorów:

Ranachowski P.-IPPT PAN
Rejmund F.-IPPT PAN
Ranachowski Z.-IPPT PAN
Jaroszewski M.-other affiliation
Pospieszna J.-other affiliation
Wieczorek K.-other affiliation
27p.
25.Ranachowski P., Rejmund F., Ranachowski Z., Pawełek A., Piątkowski A., Foundations of mechanoacoustic method of material degradation research, PRZEGLĄD ELEKTROTECHNICZNY, ISSN: 0033-2097, Vol.R 86, No.5, pp.186-198, 2010

Streszczenie:

The paper presents the concept of mechanoacoustic testing of degradation processes of ceramic electrotechnical materials. Samples of small dimensions were subjected to slowly increasing compressive loading with simultaneous recording of acoustic emission descriptors. The process was continued to the destruction or it was stopped at various stages of degradation of the material structure. Microscopic analysis of samples enabled determining the effects of stress action.

Słowa kluczowe:

acoustic emission (AE), material degradation, electrotechnical ceramics

Afiliacje autorów:

Ranachowski P.-IPPT PAN
Rejmund F.-IPPT PAN
Ranachowski Z.-IPPT PAN
Pawełek A.-other affiliation
Piątkowski A.-Institute of Metallurgy and Materials Science, Polish Academy of Sciences (PL)
9p.
26.Ranachowski P., Rejmund F., Ranachowski Z., Pawełek A., Piątkowski A., Experimental evaluation of resistance to degradation of modern C 120 type porcelain, PRZEGLĄD ELEKTROTECHNICZNY, ISSN: 0033-2097, Vol.86, No.11b, pp.126-129, 20109p.
27.Morańda H., Ranachowski P., Mościcka-Grzesiak H., Ocena porowatości porcelany na podstawie analizy wyników pomiarów wyładowań niezupełnych, PRZEGLĄD ELEKTROTECHNICZNY, ISSN: 0033-2097, Vol.86, No.11b, pp.251-253, 20109p.
28.Ranachowski P., Rejmund F., Jaroszewski M., Wieczorek K., Study of structural degradation of ceramic material of insulators in long term operation, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, Vol.54, No.1, pp.205-216, 200920p.
29.Ranachowski P., Rejmund F., Ranachowski Z., Pawełek A., Piątkowski A., Kúdela Jr. S., Materials degradation research on the basis of mechanoacoustic and microscopic methods, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, Vol.54, No.4, pp.824-832, 200920p.
30.Ranachowski P., Rejmund F., Ranachowski Z., Pawełek A., Piątkowski A., Comparison of acoustic emission and structure degradation in compressed porcelain and corundum materials, ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, Vol.34, No.4, pp.705-722, 20099p.
31.Ranachowski P., Rejmund F., Pawełek A., Piątkowski A., Structure degradation, texture and acoustic emission in compressed corundum ceramics, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, Vol.53, No.3, pp.703-709, 2008
32.Ranachowski P., Rejmund F., Pawełek A., Piątkowski A., Mechanical-acoustic study of degradation processes of ceramic structure illustrated by corundum material, PRZEGLĄD ELEKTROTECHNICZNY, ISSN: 0033-2097, Vol.84, No.10, pp.252-255, 2008
33.Ranachowski P., Rejmund F., Ranachowski Z., Pawełek A., Piątkowski A., Research of degradation processes of insulator porcelain C 130 type, ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, Vol.32, No.4S, pp.117-122, 2008

Streszczenie:

This paper presents the results of acoustic emission (AE) measurements of samples under compressive stress. Additional research, concerning structure and parameters of the material, was performed using microscopic and ultrasonic methods. The object of the investigation were samples of porcelain material C 130 type of domestic long-rod insulator LP 75/31W. This kind of aluminous porcelain demonstrates high mechanical and electrical strength as well as resistance to aging degradation processes. It finds wide application in modern electrotechnical engineering. The aim of this study was to recognize stages of degradation processes of the porcelain structure. The present work constitutes a continuation of the study concerning the influence of technological faults, existing in porcelain material structure, on long-term mechanical strength. These results were presented at the OSA Conference in 2006. The analysis of mechanical-acoustic characteristics pointed out diversified strength and complicated mechanism of the material degradation. The effectiveness of the dispersive and fibrous reinforcement of aluminous porcelain C 130 type was ascertained. It was stated during the microscopic investigation that the structure of the material is different from that in the case of typical aluminosilicate ceramic materials. The main reason for this effect is due to densely dispersed corundum and mullite fine crystals in glassy matrix.

Słowa kluczowe:

porcelain material C 130 type, acoustic emission, compressive strength, structural degradation

Afiliacje autorów:

Ranachowski P.-IPPT PAN
Rejmund F.-IPPT PAN
Ranachowski Z.-IPPT PAN
Pawełek A.-other affiliation
Piątkowski A.-Institute of Metallurgy and Materials Science, Polish Academy of Sciences (PL)
34.Ranachowski Z., Ranachowski P., Rejmund F., Pawełek A., Piątkowski A., Jasieński Z., The study of influence of high pressure torsion process on acoustic emission activity of compressed Mg - Li alloys, ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, Vol.32, No.4S, pp.123-128, 2008
35.Ranachowski Z., Rejmund F., Ranachowski P., Mechanical-acoustic method used to estimate porcelain materials degradation, POMIARY AUTOMATYKA KONTROLA, ISSN: 0032-4140, Vol.54, No.10, pp.716-719, 2008
36.Ranachowski P., Rejmund F., Pawełek A., Piątkowski A., Mechanical- acoustic and structural investigations of degradation processes of aluminous insulator porcelain C 130 type, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, Vol.52, No.4, pp.551-564, 2007
37.Ranachowski P., Rejmund F., Metody mikroskopowe w badaniach właściwości struktury ceramicznych tworzyw elektrotechnicznych, PRZEGLĄD ELEKTROTECHNICZNY, ISSN: 0033-2097, Vol.5, No.3, pp.202-205, 2007
38.Ranachowski P., Rejmund F., Bertrand J., Badania procesów starzeniowych w krystobalitowej porcelanie izolatorów długopniowych, PRZEGLĄD ELEKTROTECHNICZNY, ISSN: 0033-2097, Vol.83, No.6, pp.88-94, 2007
39.Pawełek A., Piątkowski A., Kuśnierz J., Bogucka J., Jasieński Z., Ranachowski Z., Ranachowski P., Mizera J., Kúdela S., Kúdela Jr. S., Acoustic emission in compressed Mg - Li and Al. alloys processed by ECAP, HPT and ARB methods, ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, Vol.32, No.4, pp.88-94, 2007
40.Pawełek A., Kuśnierz J., Bogucka J., Jasieński Z., Ranachowski Z., Ranachowski P., Rejmund F., Dębowski T., Acoustic emission and the Portevin-Le Chatelier effect in tensile tested Al processed by ARB technique, ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, Vol.32, No.4, pp.955-962, 2007

Streszczenie:

The paper presents the investigations of the relation between the acoustic emission (AE) and the Porte vin-Le Chatelier (PL) phenomena occurring in tensile tested two kinds of aluminium alloys: not-predeformed and predeformed earlier using the technique of accumulative rolling banding (ARB). There have been found essential correlations between AE and PL effects in ARB not-predeformed alloys. The tensile tests for ARB predeformed alloys were performed on a series of samples of various degree of work hardening and it has been observed that the correlations between the AE and PL effects are not so pronounced as in the case of ARB not-predeformed alloys. The results of AE measurements obtained using a new software allowed additionally to carry out the spectral analysis of AE signals and, in consequence, to determine the acoustic maps (acoustograms) and the spectral characteristics which are very useful in the discussion of the relations between the non-homogeneous strain mechanisms of the PL effect and the mechanisms of AE events generation. The results are discussed in the context of the existing dislocation models of the PL effect and the theoretical concepts of AE sources

Słowa kluczowe:

acoustic emission (AE), Portevin-Le Chatelier (PL) effect, tensile test, dislocations, strain mechanism, nanocrystalline and/or ultra fine-grained structure, accumulative rollbonding (ARB)

Afiliacje autorów:

Pawełek A.-other affiliation
Kuśnierz J.-other affiliation
Bogucka J.-other affiliation
Jasieński Z.-other affiliation
Ranachowski Z.-IPPT PAN
Ranachowski P.-IPPT PAN
Rejmund F.-IPPT PAN
Dębowski T.-IPPT PAN
41.Ranachowski P., Rejmund F., Pawełek A., Piątkowski A., Acoustic - mechanical and microscopic investigation of corundum material, ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, Vol.32, No.4, pp.963-970, 2007
42.Ranachowski P., Rejmund F., Bertrand J., Ocena odporności izolatorów z porcelany krystobalitowej rodzaju 112 na procesy degradacji starzeniowej, ENERGETYKA, PROBLEMY ENERGETYKI I GOSPODARKI PALIWOWO-ENERGETYCZNEJ, ISSN: 0013-7294, Vol.XII, pp.102-105, 2007
43.Ranachowski P., Rejmund F., Pawełek A., Piątkowski A., Study of degradation processes in corundum material using acoustic and microscopic methods, PRACE KOMISJI NAUK CERAMICZNYCH - POLSKI BIULETYN CERAMICZNY. CERAMIKA, ISSN: 0860-3340, Vol.101, pp.265-274, 2007
44.Ranachowski P., Rejmund F., Jaroszewski M., Ocena degradacji tworzyw ceramicznych izolatorów liniowych WN po wieloletniej eksploatacji na podstawie badań ultradźwiękowych i strukturalnych, PRZEGLĄD ELEKTROTECHNICZNY, ISSN: 0033-2097, Vol.4, pp.216-219, 2006
45.Ranachowski P., Rejmund F., Pawełek A., Piątkowski A., Investigation of influence of defectiveness in aluminous porcelain structure on fracture process under compressive loading using Acoustic Emission Method, ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, Vol.31, No.4, pp.83-90, 2006
46.Fleszyński J., Ranachowski P., Ranachowski Z., Rejmund F., Ultrasonic non-destructive diagnostics of ceramics line insulators, INSIGHT, ISSN: 1354-2575, Vol.47, pp.530-535, 2005
47.Jaroszewski M., Ranachowski P., Rejmund F., Fleszyński J., Ultradźwiękowa diagnostyka ceramicznych izolatorów liniowych po wieloletniej eksploatacji, PRZEGLĄD ELEKTROTECHNICZNY, ISSN: 0033-2097, Vol.3, pp.211-214, 2005
48.Ranachowski P., Ranachowski Z., Rejmund F., Stankiewicz J., Acoustic examination of epoxy-glass insulator material, ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, Vol.30, No.1, pp.121-130, 2005

Streszczenie:

Ultrasonic, microscopic and acoustic emission (AE) methods were applied to investigate the microstructure of composite rods, used as a carrying element of the medium voltage insulators. Such features of material structure as homogeneity level and the appearance of defects were discussed. The research was aimed at determining the influence of the technology of epoxy-glass fabrication on quality parameters of the insulator rods. The results of acoustic testing were compared with the effects of microscopic investigation.

Słowa kluczowe:

composite insulator, epoxy-glass material, nondestructive ultrasonic measurements, acoustic emission

Afiliacje autorów:

Ranachowski P.-IPPT PAN
Ranachowski Z.-IPPT PAN
Rejmund F.-IPPT PAN
Stankiewicz J.-IPPT PAN
49.Ranachowski P., Rejmund F., Pawełek A., Piątkowski A., Badania tworzywa kordierytowego przy naprężeniach ściskających w różnych temperaturach oraz po szoku termicznym, PRACE KOMISJI NAUK CERAMICZNYCH - POLSKI BIULETYN CERAMICZNY. CERAMIKA, ISSN: 0860-3340, Vol.89, pp.101-115, 2005

Lista ostatnich monografii
1.
289
Ranachowski P., Procesy starzeniowe w ceramice elektrotechnicznej, IPPT Reports on Fundamental Technological Research, 2, pp.1-262, 2011
Lista rozdziałów w ostatnich monografiach
1.
171
Ranachowski P., Ranachowski Z., Rejmund F., Brittle Matrix Composites 9, rozdział: Mechanical - acoustic and structural study of degradation processes in corundum ceramics and aluminous porcelain, Brandt A.M., Olek J., Marshall I.H., Woodhead Pub. Ltd. Cambridge and IFTR PAS, Warsaw, pp.201-214, 2009

Prace konferencyjne
1.Ranachowski Z., Jóźwiak-Niedźwiedzka D., Ranachowski P., Dąbrowski M., Kúdela Jr. S., Dvorak T., Analysis of pore distribution and connectivity in concrete using X-ray microtomography, BMC-11, 11th International Symposium on Brittle Matrix Composites, 2015-09-28/09-30, Warsaw (PL), pp.203-212, 2015

Streszczenie:

In the paper a method of X-ray microtomography (micro-CT) was employed for a direct insight into a microstructure of concrete with a practical resolution of approx. 10 micrometers3. Two sets of specimens were subjects of examination. The spatial concentration of air pores was investigated in three concretes differing in the amount of the supplement of high calcium fly ash (HCFA). The parameter of pore connectivity called diffusive tortuosity was determined in three other concretes made of the same ingredients but differing in water to cement ratio. The quantitative results obtained with application of described procedures are applicable in material characterization.

Słowa kluczowe:

X-ray microtomography, concrete, microstructure

Afiliacje autorów:

Ranachowski Z.-IPPT PAN
Jóźwiak-Niedźwiedzka D.-IPPT PAN
Ranachowski P.-IPPT PAN
Dąbrowski M.-IPPT PAN
Kúdela Jr. S.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
Dvorak T.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
2.Pawełek A., Kúdela S., Piątkowski A., Jasieński Z., Ranachowski Z., Kúdela Jr. S., Ranachowski P., Microcracking of ceramic fibres and acoustic emission in channel-die compressed mg-Li-Al alloys matrix composites, ICSV17, 17th International Congress on Sound and Vibration, 2010-07-18/07-22, Cairo (EG), pp.47-1-8, 2010

Streszczenie:

The object of investigation was the behaviour of acoustic emission (AE) during channel-die compression of the Mg-Li-Al alloys matrix composites (AMC) reinforced with ceramic δ-Al2O3fibres at room and at elevated temperature. The results of AE measurements at room temperature showed that in the majority of the investigated compositions the effect of anisotropy of the fibres distribution (planar random distribution) appeared with respect to the compression axis, whereas the AE activity at 1400C revealed a two-range character and the level of the rate of AE events was higher than thatat room temperature. These effects are discussed in terms of both, the differences in thermal expansion as well as weakening of the coherency between the fibres and the matrix. The results of AE measurements served to plot the spectral characteristics of the registered AE signals, i.e. the spectral density of AE signal as a function of its frequency. The spectral analysis of AE signals generated during the micro-cracking process of ceramic fibres in channel-die compressed Mg-Li-Al AMC was performed with the Windowed Fourier Transform method. The results are also discussed on the basis of optical and scanning microstructure images including these in-situobservations of microcracking fibres as well as in the context of the dislocation strain mechanisms and microcracking ones during the channel-die compression of the Mg-Li-Al AMC.

Afiliacje autorów:

Pawełek A.-other affiliation
Kúdela S.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
Piątkowski A.-Institute of Metallurgy and Materials Science, Polish Academy of Sciences (PL)
Jasieński Z.-other affiliation
Ranachowski Z.-IPPT PAN
Kúdela Jr. S.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
Ranachowski P.-IPPT PAN
3.Ranachowski P., Rejmund F., Ranachowski Z., Pawełek A., Piątkowski A., Mechanoacoustic study of ceramic electrotechnical material, 56th Open Seminar on Acoustics, 2009-09-15/09-18, Goniądz nad Biebrzą (PL), pp.99-104, 2009
4.Ranachowski P., Rejmund F., Ranachowski Z., Pawełek A., Piątkowski A., Mechanoacoustic study of ceramic electrotechnical material, 56th Open Seminar on Acoustics, 2009-09-15/09-18, Goniądz nad Biebrzą (PL), pp.99-104, 2009
5.Ranachowski P., Ranachowski Z., Rejmund F., Stankiewicz J., Wstępne badania procesu zaciskania okuć na prętach nośnych izolatorów kompozytowych z wykorzystaniem emisji akustycznej, VI Konferencja Naukowa Postępy w Elektrotechnologii, 2006/, Jamrozowa Polana (PL), pp.292-300, 2006

Abstrakty konferencyjne
1.Ranachowski Z., Jóźwiak-Niedźwiedzka D., Ranachowski P., Pawełek A., Kúdela Jr. S., Dvorak T., The analysis of pore distribution and pore connectivity in concrete samples using x-ray microtomography, SolMech 2014, 39th Solid Mechanics Conference, 2014-09-01/09-05, Zakopane (PL), pp.199-200, 2014

Streszczenie:

The durability of concrete in outdoor structures is closely related to its resistance against the aggressive gaseous actions coming from the environment and including influence of oxygen, nitrogen, carbon dioxide. The pore system and its interconnectivity in the concrete matrix directly influence the possibility of penetration of various aggressive gaseous media into concrete structure. The X-ray microtomography (micro-CT) is a modern, non-invasive technique enabling for determination of existing pores in the microstructure of concrete matrix. In the paper the results of investigation of two different concretes by the application of micro-CT method to micro-cores are presented. The quantitative information on the parameters of the analysed microstructure can improve the methods of material characterization available up to now.

Słowa kluczowe:

X-ray microtomography, concrete, microstructure

Afiliacje autorów:

Ranachowski Z.-IPPT PAN
Jóźwiak-Niedźwiedzka D.-IPPT PAN
Ranachowski P.-IPPT PAN
Pawełek A.-other affiliation
Kúdela Jr. S.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
Dvorak T.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)