Research On Preparation And Structure Property Of SiCp/Al Composites By High Pressure Torsion With Multi-particle Sizes

Compared with single metal material, particle reinforced metal matrix composites have many advantages such as high specific strength, good wear resistance, low coefficient of thermal expansion, and can be designed in a wide range. For the traditional preparation technology of SiCp/Al composites exist particle agglomeration, high porosity, interface reaction and other defects, this paper adopts HPT to prepare SiCp/Al composites. The HPT has advantages of low temperature, molding pressure, fast, multi-ring, which can significantly reduce the oxidation and interfacial reaction of Al matrix, enhance material density, uniform particle size distribution.In this paper, effect of high-pressure torsion on particle fracture of SiCp/Al composites was investigated by observing the microstructure of SiCp/Al composites and measuring the number, size and percentage of particles. Research effect of volume ratio on structure property of SiCp/Al Composites through prepare SiCp/Al composites with many particle sizes. Study particle size distribution, particle breakage, volume ratio on the mechanical properties of SiCp/Al composites through establish two-dimensional finite element model of SiCp/Al composites.With the increase of the twisting radius, particle fracture phenomenon is more serious, the angular of particles greatly passivated, particle number increasing, particle size decreasing and this trend will be strengthened with the increase of the volume fraction of SiC particles and particle fracture is inherent properties of particulate reinforced metal matrix composites that is prepared by high-pressure torsion.When the volume ratio is constant and the large particle size changing adding second kinds of particle size will improving the agglomeration of particles and increasing the density of material. When the size ratio is constant and the volume ratio changing, the sample with better particle size distribution has better strengthening effect. When adding many particle sizes, the sample with the more kinds of particle sizes has better tensile strength, worse plasticity. The mechanical properties of pure aluminum specimens prepared by HPT industrial pure aluminum comprehensive better than industry pure aluminum, indicate that HPT has a better consolidation of powder material.Under the condition that SiC particles and aluminum matrix have perfect interface binding and aluminum matrix haven’t defects such as impurity and hole, when particle size distribution is more uniform, particle crushing, the volume ratio is constant and small particles dominated, SiCp/Al composites have a better comprehensive performance.