摘要
采用光学显微镜、扫描电子显微镜、透射电子显微镜等设备研究了Mg-9.5Gd-3.8Y-0.6Zr合金在单向锤锻以及265℃人工时效后的显微组织。结果表明:在440℃锤锻后的Mg-Gd-Y-Zr合金中出现了大量由平行排列的短位错组成的位错阵列。这些位错阵列在晶粒内部具有近似相同的取向,彼此之间的间距约为0.3~1.4μm。由于位错阵列是高储能、大畸变区域,在后续时效过程中有诱导第二相析出作用。人工时效时,β’相会优先在位错阵列上形核和长大,取向相同且均匀的分布在位错阵列上,形成析出相链。高温时效下溶质原子扩散加剧,位错阵列会对周围的稀土溶质原子产生强烈的吸引,导致沿着析出相链形成无沉淀析出区域(PFZ)。
The microstructure of Mg-5Gd-3.8Y-0.6Zr alloy in axial hammer forging state and 265℃ageing state was studied by means of optical microscope,scanning electron microscope and transmission electron microscope.The results show that,a large number of dislocation arrays composed of parallel short dislocations appear in the Mg-Gd-Y-Zr alloy after hammer forging at 440℃.These dislocation arrays have approximately the same orientation in the grain,and the distance between them is about 0.3-1.4μm.Because the dislocation array is a high energy storage and large distortion region,it can induce the second phase precipitation in the subsequent aging process.During artificial aging,β'phase can nucleate and grow first on the dislocation array,and the precipitated phase chain is formed on the dislocation array with the same orientation and uniform distribution.The diffusion of solute atoms is intensified under high temperature aging,and the dislocation array can strongly attract the surrounding rare earth solute atoms,resulting in the formation of non-precipitated precipitation region(PFZ)along the precipitated phase chain.
作者
油超
刘楚明
万迎春
唐蓓
王必正
高永浩
蒋树农
张高龙
韩修柱
YOU Chao;LIU Chuming;WAN Yingchun;TANG Bei;WANG Bizheng;GAO Yonghao;JIANG Shunong;ZHANG Gaolong;HAN Xiuzhu(School of Materials and Engineering,Central South University,Changsha 410083,China;Tianjin Institute of Aerospace Mechanical and Electrical Equipment,Tianjin 300301,China;Beijing Institute of Spacecraft System Engineering,Beijing 100094,China)
出处
《热加工工艺》
北大核心
2020年第12期109-112,118,共5页
Hot Working Technology
