Effect of a novel sequential motion compaction process on the densification of multi-layer spray deposited 7090/SiCp composite

In the present study, a large dimension Al-10.15Zn-3.6Mg-1.8Cu-0.15Ni-0.3Zr/SiCp composite was synthesized by the multi-layer spray deposition process, then densities by a novel sequential motion compaction technique. The microstructures and mechanical properties of the multi-layer spray-deposited Al-10.15Zn-3.6Mg-1.8Cu-0.15Ni-0.3Zr/SiCp composite were studied by optical microscopy, scanning electron microscopy, and tensile tests before and after densities. The experimental results showed that sequential motion compaction technique can be used to fully density sample with large dimensions and difficult to further processing by the traditional techniques. This technique can greatly improve the microstructures and mechanical properties of the composite. The pores in the composite are elongated and closed through model pressing at the jointed effect of huge hydrostatic pressure and shearing stress. After pressed, SiC particles in the composite were broken and redistributed. Compared with the as-spray-deposited composite, the tensile properties of compaction processed composite have a great improvement not only in transverse direction but also in longitudinal direction. When the thickness reduction is about 40%, relative densities approach the theoretical density, and the actual relative density is 91.76%. The relative theoretical density is 93%.