LY12搅拌摩擦焊焊缝成型及接头微观组织分析

利用MEF3光学显微镜和JSM-6700F场发射扫描电镜分析不同焊接参数下焊缝成型特点及无缺陷致密焊接接头的微观组织变化。研究表明:对厚6mmLY12合金,当焊接速度在20mm/min时,搅拌头旋转速度在1200～900r/min间变化时焊缝致密无缺陷,其焊核区晶粒从上表面到下表面逐渐减小;等轴晶粒出现在搅拌头尺寸范围内,在搅拌头尺寸边缘地带,突然出现具有一定流向的受拉变形的晶粒带;接近轴肩的末端区域有热量输入,晶粒开始长大。

Analysis on Weld Shaping and Microstructure of Joint of Friction Stir Weld of LY12

The influence of welding parameters on the weld shaping was studied,the microstructures of joint without flaws was observed by useing OM and field emission scanning electron microscope. The results show that a good welding- joint of 6mm LY12 alloy can be attained when the rotation speed of stirrer is from 1200r/min to 900r/min and welding speed is 20mm/min.The grain size decreases gradually from up to down highly refined,equiaxed grains occur in the range of the pin size of the stirrer,and in the edge of the pin size,a directional distortion grain belt resulting from tension stress occurs suddenly,the grains near the crown start to grow due to heat is put in this region.