高压扭转制备的Mg-Sm-Ca合金组织演变及时效硬化行为  

Microstructure Evolution and Age-hardening Behavior of Mg-Sm-Ca Alloy Processed by High Pressure Torsion

作　　者：刘晓欢 李彦生 满意 王金辉 徐瑞[1] LIU Xiaohuan;LI Yansheng;MAN Yi;WANG Jinhui;XU Rui(State Key Laboratory of Metastable Materials Science and Technology,Hebei Key Laboratory of Optimizing Metal Product Technology and Performance,College of Materials Science and Engineering,Yanshan University,Qinhuangdao 066004,China)

机构地区：[1]燕山大学材料科学与工程学院,亚稳材料制备技术与科学国家重点实验室,河北省金属产品工艺与性能综合优化实验室,秦皇岛066004

出　　处：《材料导报》2021年第6期6120-6125,共6页Materials Reports

基　　金：国家自然科学基金项目(51675092)。

摘　　要：结合高压扭转(HPT)和热处理工艺研究了Mg-Sm-Ca合金的组织和力学性能的变化。光学显微镜(OM)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、显微硬度计以及X射线衍射仪(XRD)测试的结果表明,高压扭转后成功制备了纳米晶,晶粒尺寸由209μm细化至108 nm,后续时效过程中在1.5 h时达到峰值硬度134HV,约为铸态样品的2倍,与一般冷变形合金不同,组织仍为纳米晶且具有一定的抗回复性和热稳定性,同时引入了大量纳米级析出物。HPT处理后的Mg-Sm-Ca合金具有较强的(0002)基面织构,时效处理对基面滑移有促进作用,时效时间延长会使合金织构变弱。The microstructure and mechanical properties of Mg-Sm-Ca alloy were investigated by combining high pressure torsion(HPT)and aging treatment.Optical microscope(OM),scanning electron microscope(SEM),transmission electron microscope(TEM),microhardness test,and X-ray diffraction(XRD)analysis results show that nanocrystalline Mg-Sm-Ca alloy were successfully produced after HPT,and the grain size refined from 209μm to 108 nm.The peak hardness reached 134HV aged at 175℃for 1.5 h,which was about twice the as-cast sample.The structure is still nanocrystalline and has certain anti-recovery and high thermal stability,and a large amount of nano-scale precipitates is introduced,which is different from conventional cold deformed alloys.The HPT-treated Mg-Sm-Ca alloy exhibits a strong(0002)basal texture,and the aging treatment promotes basal slip.the texture of the alloy becomes weaker after aging time is prolonged.

关 键 词：Mg-Sm-Ca合金 高压扭转(HPT) 时效 织构 

分 类 号：TG146.4[一般工业技术—材料科学与工程]