Partner: Tomasz Wojciechowski

Institute of Physics, Polish Academy of Sciences (PL)

Recent publications
1.Jarząbek D.M., Milczarek M., Wojciechowski T., Dziekoński C., Chmielewski M., The effect of metal coatings on the interfacial bonding strength of ceramics to copper in sintered Cu-SiC composites, CERAMICS INTERNATIONAL, ISSN: 0272-8842, DOI: 10.1016/j.ceramint.2017.01.056, pp.1-9, 2017
Abstract:

Cu-SiC composites are very promising materials which have high thermal and electrical conductivity and may find many applications. Unfortunately, the main disadvantage of these materials is the dissolution of silicon in copper at elevated temperature, which significantly reduces their properties. In order to overcome this problem particles can be coated with a protective material before sintering. In this paper– the influence of three different metallic coatings on bonding strength were investigated. SiC particles were coated with tungsten, chromium or titanium. As reference a material with uncoated particles was prepared. The experiments were carried out with the use of microtensile tester. The highest increase in strength was observed in the case of chromium coating. On the other hand, the titanium coating, which was of very poor quality, decrease the bonding strength in comparison with uncoated particles. Furthermore, scanning electron and optical microscopes were used to determine the mechanism of debonding.

Keywords:

Interfacial bonding strength, Metal matrix composites, Tensile strength, Silicon carbide particles

Affiliations:
Jarząbek D.M.-IPPT PAN
Milczarek M.-Warsaw University of Technology (PL)
Wojciechowski T.-Institute of Physics, Polish Academy of Sciences (PL)
Dziekoński C.-IPPT PAN
Chmielewski M.-Institute of Electronic Materials Technology (PL)
2.Jarząbek D.M., Chmielewski M., Wojciechowski T., The measurement of the adhesion force between ceramic particles and metal matrix in ceramic reinforced-metal matrix composites, COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING, ISSN: 1359-835X, DOI: 10.1016/j.compositesa.2015.05.025, Vol.76, pp.124-130, 2015
Abstract:

This paper presents the method for measurement of the adhesion force and fracture strength of the interface between ceramic particles and metal matrix in ceramic reinforced-metal matrix composites. Three samples with the following Cu to Al2O3 ratio (in vol.%) were prepared: 98.0Cu/2.0Al2O3, 95.0Cu/5.0Al2O3 and 90Cu/10Al2O3. Furthermore, microwires which contain a few ceramic particles were produced by means of electro etching. The microwires with clearly exposed interface were tested with use of the microtensile tester. The microwires usually break exactly at the interface between the metal matrix and ceramic particle. The force and the interface area were carefully measured and then the fracture strength of the interface was determined. The strength of the interface between ceramic particle and metal matrix was equal to 59 ± 8 MPa and 59 ± 11 MPa in the case of 2% and 5% Al2O3 to Cu ratio, respectively. On the other hand, it was significantly lower (38 ± 5 MPa) for the wires made of composite with 10% Al2O3.

Keywords:

Nanocomposites, Metal matrix composites, Adhesion, Interface

Affiliations:
Jarząbek D.M.-IPPT PAN
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Wojciechowski T.-Institute of Physics, Polish Academy of Sciences (PL)
3.Wojnar P., Zieliński M., Janik E., Zaleszczyk W., Wojciechowski T., Wojnar R., Szymura M., Kłopotowski Ł., Baczewski L.T., Pietruchik A., Wiater M., Kret S., Karczewski G., Wojtowicz T., Kossut J., Strain-induced energy gap variation in ZnTe/ZnMgTe core/shell nanowires, APPLIED PHYSICS LETTERS, ISSN: 0003-6951, DOI: 10.1063/1.4873355, Vol.104, pp.163111-1-5, 2014
Abstract:

Strain-induced changes of ZnTe energy gap in ZnTe/ZnMgTe core/shell nanowires arising from lattice mismatch between the core and the shell semiconductor are studied by means of optical methods. It is shown that the increase of the Mg content in the shell, as well as the increase of the shell thickness result in an effective redshift of the near band edge photoluminescence from ZnTe nanowire cores, which reflects directly the decrease of energy gap under tensile strain conditions. The conclusions are supported by theoretical calculations in terms of the valence force field model. The observed change of ZnTe energy gap can be as large as 120 meV with respect to the unstrained conditions and can be tuned in a continuous manner by adjusting shell parameters, which open a path towards an effective band gap engineering in these structures.

Keywords:

Nanowires, II-VI semiconductors, Magnesium, Band gap, Quantum effects

Affiliations:
Wojnar P.-Institute of Physics, Polish Academy of Sciences (PL)
Zieliński M.-other affiliation
Wiater M.-Institute of Physics, Polish Academy of Sciences (PL)
Kret S.-Institute of Physics, Polish Academy of Sciences (PL)
Karczewski G.-other affiliation
Wojtowicz T.-Institute of Physics, Polish Academy of Sciences (PL)
Kossut J.-Institute of Physics, Polish Academy of Sciences (PL)
Janik E.-other affiliation
Zaleszczyk W.-other affiliation
Wojciechowski T.-Institute of Physics, Polish Academy of Sciences (PL)
Wojnar R.-IPPT PAN
Szymura M.-other affiliation
Kłopotowski Ł.-other affiliation
Baczewski L.T.-Institute of Physics, Polish Academy of Sciences (PL)
Pietruchik A.-Institute of Physics, Polish Academy of Sciences (PL)
4.Majkowski P., Wojciechowski T., Wojtyński M., Kotulski Z.A., Rawski M., Analiza możliwości sprzętowej kryptoanalizy szyfrów opartych na krzywych eliptycznych, POMIARY AUTOMATYKA KONTROLA, ISSN: 0032-4140, Vol.54, No.8, pp.536-539, 2008

Conference abstracts
1.Jarząbek D., Chmielewski M., Wojciechowski T., The measurement of the adhesion force between ceramic particles and metal matrix in ceramic reinforced-metal matrix composites, EUROMAT 2015, European Congress and Exhibition on Advanced Materials and Processes, 2015-09-20/09-24, Warszawa (PL), pp.1, 2015
Abstract:

This paper presents the method for measurement of the adhesion force and fracture strength of the interface between ceramic particles and metal matrix in ceramic reinforced-metal matrix composites. Three samples with the following Cu to Al 2 O 3 ratio (in vol.%) were prepared: 98.0Cu/2.0Al 2 O 3 , 95.0Cu/5.0Al 2 O 3 and 90Cu/10Al 2 O 3 . Furthermore, microwires which contain a few ceramic particles were produced by means of electro etching. The microwires with clearly exposed interface were tested with use of the microt ensile tester (Fig. 1). The microtensile tester consists of two stages, to which two endings of the microwire are fixed. The first stage is able to measure force with the precision equal to 0.1 mN. The microwires usually break exactly at the interface between the metal matrix and ceramic particle. The force and the interface area were carefully measured and then the fracture strength of the interface was determined. The strength of the interface between ceramic particle and metal matrix was equal to 59 ±8 MPa and 59±11 MPa in the case of 2% and 5% Al 2 O 3 to Cu ratio, respectively. On the other hand, it was significantly lower (38±5 MPa) for the wires made of composite with 10% Al2O3

Affiliations:
Jarząbek D.-IPPT PAN
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Wojciechowski T.-Institute of Physics, Polish Academy of Sciences (PL)
2.Jarząbek D.M., Chmielewski M., Wojciechowski T., The measurement of the adhesion force between ceramic particles and metal matrix in ceramic reinforced-metal matrix composites, Nanomechanical Testing in Materials Research and Development V, 2015-10-04/10-09, Albufeira (PT), pp.1, 2015