The Study On Reinforced Particle Pretreatement And Compound Technology Of Al Matrix Composite Reinforced By Sicp

Improving the wetability between the molten aluminum alloy and SiC particles and the particles uniformly distributed in the aluminum matrix are the keys to prepare particle reinforced aluminum matrix composites. Pickling and oxidation of the SiC particles and the particles dispersed in semisolid aluminum slurry by electromagnetic stirring process were studied.SEM and EPMA analysis that the mainly surface impurities on SiC particles were submicron SiC particles and a little Fe, Mn, V, Ni. Pickling can delete the impurities effectively which is in favor of oxidation of SiCP and the controlling of the partile agglomerates. The oxidation treatment result showed that the sharp angles and submicron SiC particles on surface were the beginning oxidation place. The oxidation inactivation of sharp angles could alleviate local stress concentration in the composite. The oxidation weight gain was significant under high oxidation-temperature. Along with the increasing of oxidation time, the weight gain velocity increased at beginning and then decreased. Up to 6h oxidation, the weight gain velocity became stable.Effect of the reinforced particle addition method, crucible and baffle size, and stirring current, stirring frequency on the preparation of slurry had been studied. The results show that electromagnetic string can improve the wetability between particles and melt. The particles distributed in the matrix uniformly under frequency 6Hz and current 500A with top adding particles.