.sic_p/zl102 The Wear Resistance Of The Composites Research And Die-casting Preparation

Aluminum matrix composites reinforced with different volume fraction of SiC particles were manufactured by semi-solid casting in this thesis. The microstructure, the hardness and the wear resistance properties of the composites fabricated by semi-solid casting has been studied and analyzed Metallographic analysis indicated that SiC particles dispersed uniformly in the composites. The Results of the hardness test showed the composites' hardness increased with the increasing volume fraction of SiC particles. Results of the wear tests showed the composites had the outstanding wear resistance properties, especially in lubricated sliding case, the wear resistance properties of the composites were superior to the matrix alloy over one or two orders of magnitude. Microscopic analysis of the abrasion surface indicated that the wear mechanism of composites and matrix alloy included sticking abrasion and grindrng-particle abrasion on the materials.The composite containing 8vol% SiC particles and the matrix alloy were die-cast into parts and particles reinforced aluminum matrix composites parts were first successfully manufactured by die-casting in domestic. Metallographic analysis indicated that SiC particles dispersed separately and more uniformly in the parts than in the ingots and the stir techniques during remelting was decisive to the die-casting of the composite. The interface between SiC particles and the alloy was clearer than that in ingots. The hardness of the parts made of composits was higher than that of the parts made of the matrix alloys. But the hardness of both kinds was higher than their ingots respectively.