Effect of Nickel-Modified SiC Particles on Compressive Damage of SiCp / 7075 Composites

The wettability between silicon carbide and aluminum is poor, silicon carbide is difficult to fuse or the distribution of silicon carbide is not uniform in the ingot when the SiCp / 7075 composite is prepared by melt casting.The surface modification of SiCp by nickel plating can significantly reduce the wetting angle of SiC/Al and improve the distribution uniformity of silicon carbide in SiCp / 7075. In this thesis, the thermal compression process 6.5% SiCp / 7075 reinforced by nickel-plated modified silicon carbide is simulated by DEFOEM-3D software.The influence of the shape and particle size of nickel-plated modified silicon carbide on its compressive damage has been highlighted, and the deformation characteristics of the SiC/Ni/Al interface layer in the thermal compression process have been discussed. The numerical simulation results show that the 6.5% SiCp / 7075 reinforced by spherical nickel-plated modified silicon carbide particles with a particle size of 15 μm has the smallest compression damage value of 0.0426, at this point the compression temperature is 400°C, the compression ratio is 15, and the compression rate is 0.03s^-1. the hot compression test of 6.5% SiCp / 7075 reinforced by spherical nickel-plated modified silicon carbide particles with a particle size of 15 μm was performed by using the same compression parameters as the numerical simulation. After hot pressing, the sample had a smooth surface with few obvious cracks, which was consistent with the numerical simulation results. Key words: nickel-plating modification; silicon carbide particles; compressive damage; grain size; grain morphology