熔体反应法制备Al3Zr(p)、Al2O3(p)/A356复合材料的凝固组织和性能

摘要

对Al-ZrOCl2体系采用熔体反应法制备了Al3Zr(p)、Al2O3(p)/A356复合材料。结果表明：原位生成的Al3Zr和Al2O3均为多面体粒状，且Al3Zr表面存在生长小面（facet）。复合材料凝固组织中随ZrOCl2加入量的增加，颗粒分数增大，颗粒分布更均匀。但反应温度高于900℃时，Al3Zr颗粒出现板块状集聚生长。拉伸试验表明：Al3Zr(p)、Al2O3(p)/A356复合材料具有比基体更高的抗拉强度，并随ZrOCl2加入量的增加而提高，其拉伸断口为混合型断裂。%Al3Zr(p)，Al2O3(p)/A356 composites have been fabricated by reaction in melt from Al-ZrOCl2 system. Results indicated that in-situ formed Al3Zr and Al2O3 are polyhedral particles.There is the faceted growth of the Al3Zr crystal.In the solidification microstructure of composites the volume fraction of particles becomes larger and Al3Zr and Al2O3 particles are well distributed in the matrix with the increasing of ZrOCl2 addition.However,the plate-like Al3Zr aggregation grows when the reactive temperature is more than 900℃.Tensile test showed that Al3Zr(p)，Al2O3(p)/A356 composites exhibited higher tensile strength than that of the matrix.The strength is enhanced with the increasing of ZrOCl2 addition.The tensile fracture is mixture of ductile and brittle.