镓中间层1420铝锂合金扩散连接方法与试验研究  

Method and Technology of Diffusion Bonding of 1420 Al-Li Alloy by Using Gallium as Interlayer

作　　者：牛涛[1] 侯红亮[1] 王耀奇[1] 张艳苓[1] 

机构地区：[1]中航工业北京航空制造工程研究所

出　　处：《航空制造技术》2015年第1期111-114,共4页Aeronautical Manufacturing Technology

基　　金：国家重点基础研究发展(国家973)计划(2011CB012803)资助

摘　　要：研究了镓对1420铝锂合金的表面活化作用,结果表明液态镓能有效破坏1420铝锂合金表面的氧化膜。基于镓中间层的表面活化作用,在力学拉伸试验机上通过机械加压方法,在试验温度520℃,连接压力7MPa,扩散时间1h条件下,对1420铝锂合金进行了扩散连接试验,并通过光学显微镜、扫描电镜和剪切强度试验等方法,对接头进行了微观分析和剪切强度测试。结果表明,中间层厚度小于1mg/cm2时,接头界面处的缝隙非常明显,焊合率较低,接头剪切强度很低,其剪切断口微观形貌光滑平整;中间层厚度大于1mg/cm2时(包括1mg/cm2),扩散连接界面完全消失,接头剪切强度明显提高,其剪切断口微观形貌中呈现沿剪切方向的撕裂带,表现为韧性断裂特征。中间层厚度为1mg/cm2时,接头剪切强度最高,达到58.35 MPa。Surface-active of gallium to 1420 AI-Li alloy is studied. The results show that, liquid gal- lium can destroy the oxide film on the surface of 1420 Al-Li alloy effectively. Basing on this, the diffusion bonding of 1420 Al-Li alloy is studied by using pure gallium as interlayer under mechanical compression force using tensile testing machine. The experiment is carried out at the bonding temperature of 520℃ under the joining pressure of 7MPa for the diffusion time of I h. The microstructure of the joints is studied by OM, SEM etc, and their mechanical properties are tested by shearing experiments. The results show that. when the thickness of the interlayer is less than lmg/cm^2, there is a clear fissure at the joint interface, the bonding ratio is very low, the shearing strength is very low, the fracture surface of the shearing test presents smooth. When the thickness of the interlayer is more than l mg/cm^2 （including l mg/cm^2）, the interface of the diffusion bonding disappears completely, the shearing strength increases obviously, the fracture surface of the shearing test presents many scratch of tearing along the tearing direction, exhibiting the characters of ductility fracture. When the thickness of the interlayer is l mg/cm^-2, the shearing strength is the highest, which is 58.35 MPa.

关 键 词：镓 铝锂合金 扩散连接 中间层 

分 类 号：TG495[金属学及工艺—焊接]