非连续增强镁基复合材料研究

采用液态浸渍法制备ＳｉＣ晶须和Ｂ４Ｃ颗粒混杂增强剂，成功地制备出增强剂含量为２４％的复合材料，并对材料的机械性能进行了测试，复合材料的抗拉强度达到了４１６ＭＰａ，弹性模量达到了８０ＧＰａ，较其基体材料分别提高了５３％和１１０％。对材料的断口分析表明，增强剂的均匀分布与晶须与基体之间的牢固结合，是复合材料具有较高机械性能的原因，而颗粒与基体界面间的开裂，以及基体共晶相的脆性开裂是复合材料塑性低的主要

RESEARCH ON DISCONTINUOUSLY REINFORCED MAGNESIUM MATRIX COMPOSITE

The pressure infiltration process has been applied in production of magnesium matrix hybrid composite in which the reinforcement is produced by a combination of SiC whisker and B 4C particle. Mechanical properties, microstructural feature, such as reinforcement distribution, and fracture morphology are investigated. It is show that a reinforcement of 12% SiC whisker 12% B 4C particle raises the elastic constant and ultimate tensile strength to 80 GPa and 416 MPa respectively, 110% and 53% increased compared with the matrix respectively. The good distribution of reinforcement after extrusion and the firm combination between whisker and matrix are used to explain the increased elastic constant and tensile strength. The low ductility found in composite is due to the interface debonding between particle and martix, and crack in the eutectic phase in the fracture process of composite.