Michał Milczarek, M.Sc., Eng.

Department of Mechanics of Materials (ZMM)
position: doctoral student
telephone: (+48) 22 826 12 81 ext.: 434
room: 239
e-mail: mmilcz

Recent publications
1.Jarząbek D.M., Milczarek M., Nosewicz S., Bazarnik P., Schift H., Size Effects of Hardness and Strain Rate Sensitivity in Amorphous Silicon Measured by Nanoindentation, METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, ISSN: 1073-5623, DOI: 10.1007/s11661-020-05648-w, pp.1-9, 2020
Abstract:

In this work, dynamic mechanical properties of amorphous silicon and scale effects were investigated by the means of nanoindentation. An amorphous silicon sample was prepared by plasma-enhanced chemical vapor deposition (PECVD). Next, two sets of the samples were investigated: as-deposited and annealed in 500 C for 1 hour. A three-sided pyramidal diamond Berkovich’s indenter was used for the nanoindentation tests. In order to determine the strain rate sensitivity (SRS), indentations with different loading rates were performed: 0.1, 1, 10, 100 mN/min. Size effects were studied by application of maximum indentation loads in the range from 1 up to 5 mN (penetrating up to approximately one-third of the amorphous layer). The value of hardness was determined by the Oliver–Pharr method. An increase of hardness with decrease of the indentation depth was observed for both samples. Furthermore, the significant dependence of hardness on the strain rate has been reported. Finally, for the annealed samples at low strain rates a characteristic ‘‘elbow’’ during unloading was observed on the force-indentation depth curves. It could be attributed to the transformation of (b-Sn)-Si to the PI (pressure-induced) a-Si end phase.

Affiliations:
Jarząbek D.M.-IPPT PAN
Milczarek M.-IPPT PAN
Nosewicz S.-IPPT PAN
Bazarnik P.-Warsaw University of Technology (PL)
Schift H.-Paul Scherrer Institut (CH)
2.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.-other affiliation
Wojciechowski T.-Institute of Physics, Polish Academy of Sciences (PL)
Dziekoński C.-IPPT PAN
Chmielewski M.-Institute of Electronic Materials Technology (PL)