Gd对Al-5Mg-2Si-Mn合金组织与力学性能的影响  

Effects of Gd on Microstructure and Mechanical Properties of Al-5Mg-2Si-Mn Alloy

作　　者：王克研 武晓峰[1] 高欣宇 赵荣达[1] 伍复发[1] Wang Keyan;Wu Xiaofeng;Gao Xinyu;Zhao Rongda;Wu Fufa(School of Materials Science and Engineering,Liaoning University of Technolog)

机构地区：[1]辽宁工业大学材料科学与工程学院

出　　处：《特种铸造及有色合金》2018年第11期1244-1247,共4页Special Casting & Nonferrous Alloys

基　　金：国家自然科学基金资助项目(51571106);辽宁省自然科学基金资助项目(2015020244;201602366)

摘　　要：研究了Gd对Al-5Mg-2Si-Mn合金铸态组织、相结构、力学性能和断口形貌的影响。研究发现,Gd对Al-5Mg-2SiMn合金中的初生α-Al及共晶Mg_2Si相具有很强的变质和细化作用,当Gd含量为0.4%时,变质和细化效果最为明显,二次枝晶间距由未变质处理的28.23μm减小到12.96μm,共晶Mg_2Si尺寸从9.38μm减少到5.07μm。且合金的力学性能显著提高,抗拉强度、伸长率和硬度(HRB)分别由未细化变质的235MPa、3.9%和33.21增加至328MPa、6.0%和43.33,合金的断裂方式由脆性断裂转变为韧性断裂。Effects of Gd on the microstructure,phase structure,mechanical properties and fracture morphology of Al-5Mg-2Si-Mn alloy were analyzed.The results reveal that the Gd element presents a strong modification and refinement effect on the primaryα-Al phase and eutectic Mg2Si phase,and the effect of modification and refinement is desirable when Gd content is 0.4%.The distance between secondary dendrites are decreased from 28.23μm un-modified ones to 12.96μm,and eutectic Mg2Si size is decreased from 9.38μm to 5.07μm.The tensile strength,elongation and hardness of the alloy treated by 0.4% Gd are increased from 235MPa,3.9%and 33.21HRB to 328MPa,6.0% and 43.33HRB,respectively,and the fracture mode is changed from brittleness to dimple structure.

关 键 词：Al-5Mg-2Si-Mn合金 GD 细化 变质 力学性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TG113.25[金属学及工艺—金属材料]