In the present work, friction stir welding of 3-mm-thick AA6061-T6 Al alloy and AZ31B-H24 Mg alloy sheets was carried out in lap configuration with Al alloy on top. Experiments were carried out by varying the pin length (3.25, 3.75, and 4.25 mm) and tool rotation speed (600, 800, and 1000 RPM). Microstructures of the joint cross-section revealed the presence of a compound intermetallic layer along the interface consisting of Al-rich (Al₃Mg₂) intermetallic compound near the Al alloy side, and Mg-rich intermetallic compound (Mg₁₇Al₁₂) near the Mg alloy side. The formation of a eutectic mixture of Mg solid solution and Mg₁₇Al₁₂ was observed at the hook on either side. Two modes of failure were observed; Mode 1 through the interface and Mode 2 due to failure of the sheet. The Mode 1 failure strengths obtained were the highest (148 ± 6 N/mm) compared to the literature and were obtained for the 3.25 and 3.75 mm pin at 800 RPM. A lap shear strength of 212 ± 6 N/mm was obtained with 4.25 mm pin length at 600 RPM, which is the highest reported so far and was attributed to Mode 2 failure. The effect of interface pull-up, angle of the interface at the advancing side, and distribution of intermetallic compounds on the lap-shear strength are discussed.

在目前的工作中，3毫米厚的Aa6061-T6铝合金和AZ31B-H24 Mg合金板的摩擦搅拌焊接以搭接方式进行，顶部为铝合金。通过改变销钉长度（3.25、3.75和4.25 mm）和工具转速（600、800和1000 RPM）进行实验。接头横截面的微观结构表明，沿着铝合金界面附近的富Al（Al ₃ Mg ₂）金属间化合物和靠近Al富Mg金属间化合物（Mg ₁₇ Al ₁₂）的界面存在化合物金属间层镁合金面。Mg固溶体与Mg ₁₇ Al ₁₂的共晶混合物的形成在两侧的钩子上观察到。观察到两种故障模式：由于纸张故障，通过接口的模式1和模式2。与文献相比，所获得的模式1破坏强度最高（148±6 N / mm），是在800 RPM下针对3.25和3.75 mm销获得的。在600 RPM时，针长为4.25 mm，搭接剪切强度为212±6 N / mm，这是迄今为止报道的最高值，归因于模式2的​​破坏。讨论了界面上拉，前进侧界面的角度以及金属间化合物的分布对搭接剪切强度的影响。