Effect of the method for producing Cu–Cr$_3$C$_2$ bulk composites on the structure and properties

[摘要] Copper–chromium carbide composites containing a carbide phase of 20–30 vol% were obtained with the use ofsolid- and liquid-phase mechanosyntheses, followed by magnetic pulse compaction (MPC) and spark plasma sintering. Themorphology, structural-phase composition, density, hardness and electrical conductivity of the composites were investigated.The structure of composites obtained by MPC represents regions of copper matrix hardened by superfine carbide precipitatessurrounded by a layer of chromium carbide. In the composites obtained by spark plasma sintering, the copper matrix hardenedby superfine carbide precipitates was divided into areas surrounded by a copper–chromium layer. A composite obtained bythe MPC of the powders synthesized using solid-phase mechano synthesis (MS) (copper, chromium and graphite) had thehighest values of Vickers microhardness (4.6 GPa) and Rockwell hardness (HRA 69). The best value of electrical conductivity(36% IACS) was achieved using liquid-phase MS (copper, chromium and xylene) and spark plasma sintering. Liquid-phaseMS is the only way to synthesize the powder with a small amount of the carbide phase and without contamination.

[学科分类] 材料工程

[关键词] Mechanosynthesis;nanocomposites;copper;chromium carbide.