Effect of silicon carbide particles on the mechanical and plastic properties of the AlMg6/10% SiC metal matrix composite

This work deals with studying the effect of reinforcing SiC particles on the mechanical and plastic properties of a metal matrix composite with a matrix of aluminum alloy AlMg6 (the 1560 aluminum alloy according to the Russian State Standard GOST 4784−97). We assess this effect using the results of mechanical tests at the microscale and macroscale levels. The paper analyzes the fracture mechanism at the microlevel under tensile and compressive stress conditions, as well as the type of contact between the composite constituents. The experimental results obtained for the metal matrix composite are compared with analogous experimental data for the AlMg6 alloy and a compacted material made from the AlMg6 alloy (a compacted powder without addition of SiC reinforcing particles). The studied compacted materials were not previously subjected to extrusion. The tests show a decisive influence of the reinforcing particles on the plastic and mechanical properties of the AlMg6/10% SiC metal matrix composite under compression and tension. For example, the addition of silicon carbide increased the initial yield stress of the compacted material by 26% under tensile tests, and the percentage elongation after fracture was increased up to 1.1%, while it amounted to 0.02% for the compacted material without addition of silicon carbide. Under compression, on the contrary, the addition of silicon carbide degraded plastic properties. As a result, the percentage compression before cracking was 28.4% and 57.9% for the compacted materials with and without addition of silicon carbide, respectively.