【摘要】 采用不同的轴肩直径,以不同的热输入进行了2 mm厚新型轻合金Mg-8Al-1Zn-0.3Y的搭接搅拌摩擦点焊试验,并分析了接头的显微组织、显微硬度和剪切拉伸性能。结果表明,随轴肩直径从10 mm增大至20 mm的热输入逐渐增大,焊核区晶粒先细化后粗化,接头的剪切拉伸性能呈现出先提高后下降的变化趋势,但接头横截面显微硬度无明显变化。更多还原

【Abstract】 Using different-diameter shaft shoulders, the experiments of friction stir spot welding of new lightweight alloy Mg-8Al-1Zn-0.3Y with the thickness of 2 mm were carried out under different heat input, and the joint’s microstructure,micro-hardness, shear and tensile properties were analyzed. The results show that, with the increase of shoulder diameter from 10 mm to 20 mm, the heat input increases gradually, the grain size in welding nugget area becoms coarse after refining first, joint shear and tensile performance also show a trend of first increasing and then declining, but the joint micro-hardness at cross-section has no obvious changes.更多还原