喷射成形高锰ZA35合金的工艺及组织研究

Research on Processing and Microstructure of Spray Forming ZA35 Alloy with High Mn Amount

利用优化工艺参数的喷射成形技术制备含Mn3.5%(质量分数,下同)的ZA35合金坯,比较了铸态和喷射成形态合金的微观组织。研究表明:喷射成形态合金晶粒细小,组织分布均匀;元素Mn在铸态组织中主要以大量富Mn独立硬化相分布于晶界或晶界附近,喷射成形合金组织中富Mn相消失,元素Mn溶入基体,固溶度明显提高。元素Mn在铸态和喷射成形态合金基体中分布规律一致,即在α富铝相中的固溶度显著高于在η富锌相中的固溶度。热挤压后,喷射成形3.5%Mn-ZA35中有类似纳米级晶须状和颗粒状的MnAl6析出。

The ZA35 alloy with 3.5%（mass fraction,the same below） Mn is manufactured with spray forming technique using the optimized parameters.The microstructure of the alloy（casting,spray forming） are observed.It is indicated that the microstructures of spray formed high Mn ZA35 alloy distribute homogeneous and the grains are refined.The element Mn exists mainly in the form of Mn-enriched independent hard phase in or near the interfaces of grains of casting ZA35 alloy,but the Mn-enriched independent hard phases are not found in spray formed high Mn ZA35 alloy.The solid solubility of Mn in ZA35 matrix is shifted considerably to a higher level by spray forming.The distribution of element Mn in casting and spray forming ZA35 matrix is uniform,the solid solubility in α phase is higher than in η phase.The nano whisker and particle of MnAl6 is obtained in spray formed high Mn ZA35 alloy after heat squeezing.