热轧及热处理对Mg-Y-Nd合金组织的影响  

Effect of hot rolling and thermal treatment on microstructure of Mg-Y-Nd alloy

作　　者：宋波[1] 辛仁龙[1,2] 陈刚[1] 孙立云[1] 刘庆[1,2] 

机构地区：[1]重庆大学材料科学与工程学院,重庆400044 [2]重庆大学国家镁合金工程技术研究中心,重庆400045

出　　处：《中国有色金属学报》2013年第10期2721-2729,共9页The Chinese Journal of Nonferrous Metals

基　　金：国家重点基础研究发展计划资助项目(2007CB613703);国家自然科学基金重大项目(50890172);中央高校基本科研业务费资助(CDJZR10130015;CDJXS12130002)

摘　　要：考察热轧工艺及随后热处理对Mg-Y-Nd合金组织演变的影响。结果表明:低温(<500℃)轧制时,大量稠密析出相的出现致使轧制性能极大地降低且组织难以细化;在固溶温度下轧制(525℃)时,晶粒极易粗化;当轧制温度略低于固溶温度时,轧制过程中会析出弥散的第二相粒子。这些粒子的存在没有恶化轧制性能且有效地钉扎晶界并抑制高温下再结晶晶粒的粗化。该合金的较佳轧制工艺如下:轧制温度为500℃、每道次轧制变形量为10%且总轧制变形量70%。热轧后,材料获得平均晶粒尺寸为30μm左右的组织,并产生较强的基面织构。固溶处理1 h可有效地消除位错并维持细晶和基面织构。进一步增加固溶时间,晶粒发生粗化且织构变得分散。相比于均匀化态,经T6处理的热轧态Mg-Y-Nd合金的屈服强度提高176 MPa。The effects of hot-rolling and the following heat treatment on microstructure were investigated. The results show that, for rolling below 500 ℃, the dense precipitates are formed, which is bad for further rolling and grain refinement. However, rolling at the solution temperature （525 ℃）, the recrystallization grains grow rapidly and coarsen. When rolling temperature is slightly lower than the solution temperature, dispersion particles are precipitated, which are not harmful for further rolling and are capable of pinning grain boundary to resist coarsening of recrystallization grains at high temperature. The better rolling processing parameters are that the rolling temperature is 500 ℃, the thickness reduction per pass is 10% and the total thickness reduction is 70%. After hot-rolling, the fine and uniform microstructure with an average size of approximately 30 ~tm and a strong basal texture are obtained. The solution treatment for lh can effectively eliminate dislocation and retain the same grain size and texture. As solution time further increases, the grain coarsens and texture becomes dispersive. Compared to the as-received alloy, the yield strength of the hot-rolled Mg-Y-Nd alloy with T6 treatment is increased by 176 MPa.

关 键 词：Mg-Y-Nd合金 热轧 热处理 显微组织 织构 

分 类 号：TG146.2[一般工业技术—材料科学与工程]