超声作用时间对超声辅助瞬间液相扩散连接MB8/Ni/LY12异种金属接头形成的影响

Effect of Ultrasonic Treatment Time on Formation of MB8/Ni/LY12 Dissimilar Alloy Joints by Ultrasound-assisted Transient Liquid Phase Bonding

采用纯镍中间层对镁/铝异种合金进行超声辅助瞬间液相扩散焊(U-TLP),实现大气环境下无钎剂快速有效连接。结果表明:在520℃时,超声10 s,Mg母材首先与Ni箔发生共晶反应,生成Mg_(2)Ni+α-Mg共晶液相,Al侧存在破碎的母材和中间层颗粒,无明显反应物。随着超声作用时间延长至15 s时,Al母材与Ni发生扩散连接生成Al_(3)Ni层。在超声30 s时,Ni箔消失,接头内产生大量Al_(3)Mg_(2)、Al_(12)Mg_(17),其严重影响了接头的连接,剪切强度仅为20.2 MPa。当超声时间为15 s时,剪切强度达到最大值31.2 MPa,断裂位置是接头中Al侧Al_(3)Ni层。

Ultrasound-assisted transient liquid phase bonding(U-TLP)of magnesium/aluminum alloy was carried out with a pure nickel interlayer to achieve rapid and effective bonding without flux in air.The results show that Mg base metal firstly reacts with Ni foil to form Mg_(2)Ni+α-Mg eutectic liquid phase at 520℃for 10 s with the assistance of ultrasound,and there are broken Al base metal and interlayer particles on the Al side.When ultrasonic treatment time is 15 s,the Ni and Al elements diffuse into each other to form the Al_(3)Ni interlayer.When the ultrasonic treatment time is 30 s,the Ni foil disappears and a large amount of Al_(3)Mg_(2)and Al_(12)Mg_(17)form in the joint,which seriously affects the connection of joint,and the shear strength is only 20.2 MPa.When the ultrasonic time is 15 s,the shear strength reaches the maximum value of 31.2 MPa,the fracture position is located at the Al_(3)Ni layer at Al side.