ZK60合金粉末烧结和热挤压后的组织与性能  

The properties and microstructure of rapidly solidified ZK60 magnesium alloy fabricated by sintering and hot extrusion process

作　　者：张振亚[1] 赵奇[2] 于化顺[1] 王少卿[1] 王海涛[1] 闵光辉[1] 

机构地区：[1]山东大学材料液态结构及其遗传性教育部重点实验室,济南250061 [2]南山学院材料系,山东烟台265713

出　　处：《粉末冶金技术》2009年第6期434-437,441,共5页Powder Metallurgy Technology

摘　　要：采用雾化法制得ZK60合金粉末，并用掺胶法制备ZK60合金棒材，研究热挤压后ZK60合金的微观组织、相组成及力学性能。结果表明：合金粉末主要由α-Mg固溶体构成，呈枝品与等轴晶混合组织，晶粒尺寸5—10μm；在后续热挤压过程中粉末之间结合良好，晶粒进一步细化，同时合金基体中大量析出MgZn2球形纳米颗粒；经T5（175℃保温12h）热处理后，析出相密度呈增加趋势。挤压变形后材料的屈服强度（σ0.2）、最大抗拉强度（σUTS）和伸长率（δ）分别为286．3MPa、337．7MPa及5．6％；随后T5处理可进一步提高强度（σ0.2=300．1MPa，σUTS=340．5MPa），增加塑性（δ=12．3％）。Rapidly solidified （RS） ZK60 magnesium alloy powders and ZK60 bars were produced by atomization method and powder metallurgy process consisting of cold compaction, sintering and hot extrusion, respectively. The microstructure, phase compositions and mechanical properties of as-extruded RS ZK60 bars were investigated. The results show that the RS ZK60 magnesium alloy powders are composed of dendritic and equiaxed mixed microstructures with grain size of 5 - 10μm, which is formed in supersaturated solid solution of α-Mg phase. During extrusion, RS powders are welded very well and grains are further refined through dynamic recrystallization. Typical TEM shows that nanoscale spherical precipitates 13-MgZn2 disperse in the supersaturated α-Mg after extrusion and T5 （175℃- 12h） heat treatment, with density increasing gradually. The yield strength（ σ0.2）, uhimate tensile strength （σUTS） and elongation （δ） of as-extruded RS ZK60 alloy are 286.3MPa,337.7MPa and 5.6% respectively. After subsequent annealing treatment, both the strengths and elongation can be increase simuhaneously （σ0.2= 300. 1 MPa, δUTS =340.5 MPa, δ=12.3%）.

关 键 词：快速凝固 ZK60 组织 力学性能 

分 类 号：TF124.5[冶金工程—粉末冶金] TG146.22[冶金工程—冶金物理化学]