Partner: Rafał Zybała

Warsaw University of Technology (PL)

Recent publications
1.Chmielewski M., Pietrzak K., Teodorczyk M., Nosewicz S., Jarząbek D., Zybała R., Bazarnik P., Lewandowska M., Strojny-Nędza A., Effect of metallic coating on the properties of copper-silicon carbide composites, APPLIED SURFACE SCIENCE, ISSN: 0169-4332, DOI: 10.1016/j.apsusc.2016.12.130, Vol.421, pp.159-169, 2017
Abstract:

In the presented paper a coating of SiC particles with a metallic layer were used to prepare copper matrix composite materials. The role of the layer was to protect the silicon carbide from decomposition and dissolution of silicon in the copper matrix during the sintering process. The SiC particles were covered by chromium, tungsten and titanium using Plasma Vapour Deposition method. After powder mixing of components, the final densification process via Spark Plasma Sintering (SPS) method at temperature 950C was provided. The almost fully dense materials were obtained (> 97.5%). The microstructure of obtained composites was studied using scanning electron microscopy as well as transmission electron microscopy. The microstructural analysis of composites confirmed that regardless of the type of deposited material, there is no evidence for decomposition process of silicon carbide in copper. In order to measure the strength of the interface between ceramic particles and the metal matrix, the micro tensile tests have been performed. Furthermore, thermal diffusivity was measured with the use of the laser pulse technique. In the context of performed studies, the tungsten coating seems to be the most promising solution for heat sink application. Compared to pure composites without metallic layer, Cu-SiC with W coating indicate the higher tensile strength and thermal diffusitivy, irrespective of an amount of SiC reinforcement. The improvement of the composite properties is related to advantageous condition of Cu-SiC interface characterized by well homogenity and low porosity, as well as individual properties of the tungsten coating material.

Keywords:

metal matrix composites, silicon carbide, metallic layers deposition, thermal conductovity, interface strength

Affiliations:
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Pietrzak K.-other affiliation
Teodorczyk M.-other affiliation
Nosewicz S.-IPPT PAN
Jarząbek D.-IPPT PAN
Zybała R.-Warsaw University of Technology (PL)
Bazarnik P.-Warsaw University of Technology (PL)
Lewandowska M.-other affiliation
Strojny-Nędza A.-Institute of Electronic Materials Technology (PL)
2.Chmielewski M., Pietrzak K., Strojny-Nędza A., Kaszyca K., Zybala R., Bazarnik P., Lewandowska M., Nosewicz S., Microstructure and thermal properties of Cu-SiC composite materials depending on the sintering technique, SCIENCE OF SINTERING, ISSN: 0350-820X, DOI: 10.2298/SOS1701011C, Vol.49, pp.11-22, 2017
Abstract:

The presented paper investigates the relationship between the microstructure and thermal properties of copper–silicon carbide composites obtained through hot pressing (HP) and spark plasma sintering (SPS) techniques. The microstructural analysis showed a better densification in the case of composites sintered in the SPS process. TEM investigations revealed the presence of silicon in the area of metallic matrix in the region close to metal ceramic boundary. It is the product of silicon dissolving process in copper occurring at an elevated temperature. The Cu-SiC interface is significantly defected in composites obtained through the hot pressing method, which has a major influence on the thermal conductivity of materials.

Keywords:

Metal matrix composites; Silicon carbide; Interface; Spark plasma sintering; Thermal conductivity.

Affiliations:
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Pietrzak K.-IPPT PAN
Strojny-Nędza A.-Institute of Electronic Materials Technology (PL)
Kaszyca K.-other affiliation
Zybala R.-Warsaw University of Technology (PL)
Bazarnik P.-Warsaw University of Technology (PL)
Lewandowska M.-other affiliation
Nosewicz S.-IPPT PAN
3.Zybała R., Schmidt M., Kaszyca K., Ciupiński Ł., Kruszewski M.J., Pietrzak K., Method and Apparatus for Determining Operational Parameters of Thermoelectric Modules, Journal of Electronic Materials, ISSN: 0361-5235, DOI: 10.1007/s11664-016-4712-1, Vol.45, No.10, pp.5223-5231, 2016
Abstract:

The main aim of this work was to construct and test an apparatus for characterization of high temperature thermoelectric modules to be used in thermoelectric generator (TEGs) applications. The idea of this apparatus is based on very precise measurements of heat fluxes passing through the thermoelectric (TE) module, at both its hot and cold sides. The electrical properties of the module, under different temperature and load conditions, were used to estimate efficiency of energy conversion based on electrical and thermal energy conservation analysis. The temperature of the cold side, Tc, was stabilized by a precise circulating thermostat (≤0.1°C) in a temperature range from 5°C to 90°C. The amount of heat absorbed by a coolant flowing through the heat sink was measured by the calibrated and certified heat flow meter with an accuracy better than 1%. The temperature of the hot side, Th, was forced to assumed temperature (Tmax = 450°C) by an electric heater with known power (Ph = 0–600 W) with ample thermal insulation. The electrical power was used in calculations. The TE module, heaters and cooling plate were placed in an adiabatic vacuum chamber. The load characteristics of the module were evaluated using an electronically controlled current source as a load. The apparatus may be used to determine the essential parameters of TE modules (open circuit voltage, Uoc, short circuit current, Isc, internal electrical resistance, Rint, thermal resistance, Rth, power density, and efficiency, η, as a function of Tc and Th). Several commercially available TE modules based on Bi2Te3 and Sb2Te3 alloys were tested. The measurements confirmed that the constructed apparatus was highly accurate, stable and yielded reproducible results; therefore, it is a reliable tool for the development of thermoelectric generators.

Keywords:

energy conversion efficiency, power generation, thermoelectric modules, performance characterization, heat recovery, renewable energy

Affiliations:
Zybała R.-Warsaw University of Technology (PL)
Schmidt M.-Institute of Electronic Materials Technology (PL)
Kaszyca K.-other affiliation
Ciupiński Ł.-Warsaw University of Technology (PL)
Kruszewski M.J.-other affiliation
Pietrzak K.-other affiliation
4.Pietrzak K., Sobczak N., Chmielewski M., Homa M., Gazda A., Zybała R., Strojny-Nędza A., Effects of Carbon Allotropic Forms on Microstructure and Thermal Properties of Cu-C Composites Produced by SPS, Journal of Materials Engineering and Performance, ISSN: 1059-9495, DOI: 10.1007/s11665-015-1851-0, Vol.25, No.8, pp.3077-3083, 2016
Abstract:

Combination of extreme service conditions and complex thermomechanical loadings, e.g., in electronics or power industry, requires using advanced materials with unique properties. Dissipation of heat generated during the operation of high-power electronic elements is crucial from the point of view of their efficiency. Good cooling conditions can be guaranteed, for instance, with materials of very high thermal conductivity and low thermal expansion coefficient, and by designing the heat dissipation system in an accurate manner. Conventional materials such as silver, copper, or their alloys, often fail to meet such severe requirements. This paper discusses the results of investigations connected with Cu-C (multiwall carbon nanotubes (MWNTs), graphene nanopowder (GNP), or thermally reduced graphene oxide (RGO)) composites, produced using the spark plasma sintering technique. The obtained composites are characterized by uniform distribution of a carbon phase and high relative density. Compared with pure copper, developed materials are characterized by similar thermal conductivity and much lower values of thermal expansion coefficient. The most promising materials to use as heat dissipation elements seems to be copper-based composites reinforced by carbon nanotubes (CNTs) and GNP.

Keywords:

copper matrix composites, graphene, spark plasma sintering, thermal properties

Affiliations:
Pietrzak K.-other affiliation
Sobczak N.-other affiliation
Chmielewski M.-Institute of Electronic Materials Technology (PL)
Homa M.-Foundry Research Institute (PL)
Gazda A.-Foundry Research Institute (PL)
Zybała R.-Warsaw University of Technology (PL)
Strojny-Nędza A.-Institute of Electronic Materials Technology (PL)