Effect of spark plasma sintering and high-pressure torsion on the microstructural and mechanical properties of a Cu–SiC composite

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 2019-10, Vol.766, p.138350, Article 138350
• Main Authors: Bazarnik, P., Nosewicz, S., Romelczyk-Baishya, B., Chmielewski, M., Strojny Nędza, A., Maj, J., Huang, Y., Lewandowska, M., Langdon, T.G.
• Format: Article
• Language: English
• Subjects: Copper; Densification; Grain refinement; Heat conductivity; Heat transfer; High-pressure torsion; Mechanical properties; Metal matrix composites; Microhardness; Microscopy; Microstructural analysis; Microstructure; Plasma sintering; Plastic deformation; Polymer matrix composites; Scanning electron microscopy; Scanning transmission electron microscopy; Silicon carbide; Spark plasma sintering; Thermal conductivity; Torsion
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2019.138350

This investigation examines the problem of homogenization in metal matrix composites (MMCs) and the methods of increasing their strength using severe plastic deformation (SPD). In this research MMCs of pure copper and silicon carbide were synthesized by spark plasma sintering (SPS) and then further processed via high-pressure torsion (HPT). The microstructures in the sintered and in the deformed materials were investigated using Scanning Electron Microscopy (SEM) and Scanning Transmission Electron Microscopy (STEM). The mechanical properties were evaluated in microhardness tests and in tensile testing. The thermal conductivity of the composites was measured with the use of a laser pulse technique. Microstructural analysis revealed that HPT processing leads to an improved densification of the SPS-produced composites with significant grain refinement in the copper matrix and with fragmentation of the SiC particles and their homogeneous distribution in the copper matrix. The HPT processing of Cu and the Cu–SiC samples enhanced their mechanical properties at the expense of limiting their plasticity. Processing by HPT also had a major influence on the thermal conductivity of materials. It is demonstrated that the deformed samples exhibit higher thermal conductivity than the initial coarse-grained samples.