真空脱氢对Sr变质ZL114A焊缝组织性能影响  

Effect of Vacuum Dehydrogenation on Welding Microstructure and Mechanical Properties of ZL114A Alloy Modified by Strontium

作　　者：樊振中 熊艳才[1,2] 陆政 郑卫东 王端志 孟德浩 Fan Zhenzhong;Xiong Yancai;Lu Zheng;Zheng Weidong;Wang Duanzhi;Meng Dehao(AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China;Beijing Advanced Engineering Technology and Application Research Center of Aluminum Materials,Beijing 100095,China;Beijing Institute of Astronautical Systems Engineering,Beijing 100076,China)

机构地区：[1]中国航空工业集团公司北京航空材料研究院,北京100095 [2]北京市先进铝合金材料及应用工程技术研究中心,北京100095 [3]北京宇航系统工程研究所,北京100076

出　　处：《稀有金属材料与工程》2019年第1期227-234,共8页Rare Metal Materials and Engineering

基　　金：中国航发北京航空材料研究院基金(KJSC160206)

摘　　要：采用电感耦合法(ICP)、电子测氢仪、万能试验机、金相显微镜(OM)、扫描电镜(SEM)、能谱分析(EDS)与透射电镜(TEM)研究了真空脱氢对Sr变质ZL114A合金焊缝区域微观组织与力学性能的影响。结果表明:焊接副与焊丝经真空脱氢处理,氢含量由0.64×10^(-6)降至0.26×10^(-6),24与12 mm焊缝区域气泡数量分别降低71.4%与60%,气泡直径由2.3,1.8 mm降至1.4,1.2 mm,面密度各降低77.7%,81.8%。沿晶界均匀分布的共晶Si相经添加Sr元素后,形貌由针状转变为球状,颗粒尺寸由106降至12μm,12 mm焊缝区域平均抗拉强度、屈服强度、延伸率与断面收缩率分别为364 MPa,332 MPa,9.8%与14.2%。T6态微观组织主要由初生α-Al、初生及共晶Si相与Mg_2Si相组成,断口表面硬脆Si相颗粒直径约为4μm,Mg_2Si相呈长棒状,长宽比约为15.2,经真空脱氢处理,断口韧窝形貌由椭圆状过渡为球状,断裂机制由沿晶断裂演变为韧窝断裂。The effect of vacuum dehydrogenation on microstructure and mechanical properties of ZL114A alloy modified by Sr nearbywelding region were analyzed by Electronic hydrogen measuring instrument, ICP, OM, SEM, EDS, TEM and Universal testing machine.The results show that after the vacuum dehydrogenation process the hydrogen content decreases from 0.64×10-6 to 0.26×10-6;in the 24 mmand 12 mm weld zone, the number of bubbles decreases by 71.4% and 60%, their diameter decreases from 2.3 and 1.8 to 1.4 and 1.2 mm,and the surface density is reduced by 77.7% and 81.8%, respectively. The morphology of silicon phase transforms from needle-like tospherical, the particle size decreases from 106 to 12 μm. the average tensile strength, yield strength, elongation and reduction of area with12 mm in thickness are 364 MPa, 332 MPa, 9.8% and 14.2%, respectively. The microstructure under T6 state mainly contains primaryα-Al, primary and eutectic Si phase and Mg2Si aging phase, the diameter of brittle Si particle is 4 μm, Mg2Si aging phase shows a rod-likemorphology and the aspect ratio is 15.2. The shape of dimple changes from elliptical to spherical and the fracture mechanism evolves fromintergranular fracture to dimple rupture after vacuum dehydrogenation.

关 键 词：真空脱氢 ZL114A合金 硅相变质 力学性能 微观组织 

分 类 号：TG146.21[一般工业技术—材料科学与工程]