高能球磨对Mg-Zn-Zr合金微观组织与力学性能的影响  

Effect of High Energy Milling on the Microstructure and Mechanical Properties of Mg-Zn-Zr Alloy

作　　者：李小强 李尚鹏 丁艳林 马国俊[1] 金培鹏[1] LI Xiaoqiang LI Shangpeng DING Yanlin MA Guojun JIN Peipeng(Qinghai Provincial Key Laboratory of New Light Alloys,Qinghai Provincial Engineering Research Center of High Performance Light Metal Alloys and Forming, Qinghai University, Xining 810016)

机构地区：[1]青海大学青海省高性能轻金属合金及深加工工程技术研究中心青海省新型轻合金重点实验室,西宁810016

出　　处：《材料导报》2017年第18期77-80,91,共5页Materials Reports

基　　金：国家自然科学基金(51661028);青海省科技厅基础研究项目(2015-ZJ-736)

摘　　要：在氩气条件下以400r/min高能球磨镁合金粉末,并将球磨后的粉末经过冷压—热压烧结—热挤压成型。研究了不同球磨时间的粉末以及挤压态样品的微观组织和力学性能。结果表明:随着球磨时间的延长,粉末颗粒尺寸可以细化到8μm,晶粒尺寸有效细化到34nm,在整个球磨过程中粉末有一定程度的氧化,并伴随有MgO纳米颗粒产生。粉末经过热压烧结—热挤压成型后,材料内部有MgZn2相颗粒析出,且均匀分布于Mg基体中。随着粉末颗粒的细化,材料性能得到改善,当球磨至10h时,粉末挤压态样品的极限拉伸强度为365 MPa,压缩屈服强度高达325 MPa,极限压缩强度保持在466 MPa。球磨至25h,颗粒平均尺寸细化至8μm左右,使得颗粒表面能大幅度增大,颗粒表面的氧化膜增厚,在热压烧结过程中阻碍了颗粒之间的结合,进而使得材料的力学性能恶化。High-energy milling of Mg alloy powder was conducted in argon atmosphere,and then the cold-pressing,hotpressing sintering and hot extrusion of the milled powder was performed.The microstructure and mechanical properties of the as-extruded samples at different ball milling conditions was studied.The results indicated that with the increasing milling time,the particle size was refined to 8μm,and grain size was about 34 nm,oxidation of the powders still occurred during the process,nano-MgO particles were also produced.Precipitated phase（MgZn2）existed in the extruded alloys,and uniformly distributed in the Mg matrix.With refined particles,the material performance was significantly improved,when the milling time was up to 10 h,the ultimate tensile strength and compress yield strength of the as-extruded samples were 365 MPa and 325 MPa,respectively,the ultimate compression strength kept in 466 MPa.When the milling time was 25 h,the average particle size of the powders was about 8μm,accompanied with increased surface energy and thickened oxide film of the particles,which resulted in the bad combination between particles and opposite effect on the mechanical properties of the material.

关 键 词：镁合金粉末 高能球磨 热压烧结 MGO 纳米颗粒 

分 类 号：TB31[一般工业技术—材料科学与工程]