SiC_w/6061Al复合材料无钎剂加压钎焊

Fluxless Pressure Soldering for SiC_ w /6061Al Composites

提出一种新的钎焊方法———无钎剂加压钎焊 ,采用Zn -Al钎料进行了SiCW/60 61Al复合材料的焊接试验 ,研究了温度、压力两工艺参数对接头强度及微观组织的影响规律 ,并初步分析了辅助工艺———机械刮擦的作用。试验发现 ,温度和压力是至关重要的钎焊工艺参数 ,当温度在 4 0 0～ 4 5 0℃ ,压力为 3 0MPa时 ,接头拉伸破坏于钎缝处 ,强度达到 2 63 .3MPa ,为母材抗拉强度的 85 %～ 90 %。采用扫描电镜分析断口 ,发现其形貌为小韧窝 +准解理 +SiC晶须 ,还存在被拉伸拔掉的SiC晶须残留的凹坑 ,这证明了SiC晶须在钎缝中的强化作用。X射线衍射相结构分析表明 ,断口是由α -Al(Zn)固溶体基体上均匀分布着SiC晶须组成 ,这同时表明钎缝主要有α -Al(Zn)基体 +SiC晶须组成。

A new soldering method fluxless pressure soldering for SiC w /6061Al composites was presented,and welding experiments for the effects of two parameters: the soldering temperature and pressure related to soldered joint strength and microstructure were carried out by using the Zn Al filler metal.The contribution of assistant process scrape was also discussed.The experimental results show that temperature and pressure are two key soldering process parameters,when the soldering temperature is in the range of 400～450 ℃ and the pressure is 30 MPa,the tensile strength of soldered joint reaches 252.0～263.3MPa,which is up to 85%～90% of that of base metal.A number of microdimples,SiC w whiskers,considerable quasicleavage together with residual pits of SiC whiskers are observed on the fracture,which identifies the reinforcement of SiC whiskers to the soldering seam.Moreover,the results of X ray diffraction analysis indicate that the soldering seam mainly consists of a Al(Zn) solid solution and uniform SiC whiskers.