时效对Mg-Nd-Zn-Zr合金组织及硬度的影响  

Effect of aging on microstructure and hardness of Mg-Nd-Zn-Zr alloy

作　　者：郭英健 马少博[2] 赵莉萍[1] 

机构地区：[1]内蒙古科技大学材料与冶金学院,内蒙古包头014010 [2]包头稀土研究院,内蒙古包头014010

出　　处：《金属热处理》2017年第12期155-159,共5页Heat Treatment of Metals

摘　　要：对Mg-Nd-Zn-Zr合金进行时效处理,研究了该合金在不同时效条件下的组织和硬度。结果表明:固溶过程中,离异共晶的第二相不是直接溶解进入α-Mg基体中,而是以Zn元素向未溶解的第二相中富集,并因Nd在晶粒内侧富集而形成Mg-Nd相。在200℃时效时,合金的硬度先升高后下降,峰时效时间为2~4 h,峰时效硬度为72 HV0.5左右。在200℃时效过程中,析出相由颗粒状向针状逐渐变化,弥散分布的针状析出相Mg5Nd为主要强化相。Microstrueture and hardness of Mg-Nd-Zn-Zr alloy under different aging conditions were studied. The results show that the second phase of the divorced eutectic is not directly dissolved into the α-Mg matrix during the solid solution treatment, but the Zn element is enriched in the undissolved second phase and Mg-Nd phase torms due to the enrichmenl of Nd at the inner side of grains. During the aging process at 200 %, the hardness of the alloy first increases and the,a decreases, with the peak aging time Deing 2-4 h, and the peak aging hardness about 72 HV0.5. The precipitated phase gradually changed from granular to needle-like in the process, and the dispersed phase of the needle-like precipitate MgsNd become the main strengthening phase.

关 键 词：Mg-Nd-Zn-Zr合金 稀土Nd 时效 组织 硬度 

分 类 号：TG156.92[金属学及工艺—热处理]