6063铝合金管件磁脉冲辅助钎焊工艺研究

Study on Magnetic Pulse Assisted Brazing Process of 6063 Aluminum Alloy Pipe

将Zn-3Al焊料片置于6063铝合金待焊内外管材径向间隙中,采用磁脉冲预成形技术成形铝合金待焊接头,然后使用高频感应加热装置对预成形后的待焊接头进行了钎焊连接。研究了不同放电电压、管材间隙及钎料片厚度对磁脉冲预成形铝合金待焊接头的结合性能、均匀性系数及成形状态的影响,并对比分析了不同钎焊温度时接头的界面冶金结合状态及显微形貌。结果表明,在放电电压12 k V、管件间隙1.5 mm、钎料片150μm时得到的待焊接头具有良好的外观、管件贴合度及结合强度;在420℃钎焊5 s获得的钎焊接头,其界面结合效果好,在钎料合金与铝母材结合面形成了连续的元素扩散层,钎料层中无任何孔洞及裂纹等焊接缺陷。钎料层由α-Al先共晶相和细小均匀的Zn-Al共晶相组成。

Zn-3 Al filler metal slice was placed in the gap between the inner and outer pipes of 6063 aluminum alloy, and the aluminum alloy prewelded joint was formed by using magnetic pulse preforming technology, then the prewelded joint was brazed by using high-frequency induction heating device. The effects of discharge voltage, pipe-to-pipe gap and thickness of filler metal slice on the bonding properties, uniformity coefficient and forming state of the magnetic pulse preforming aluminum alloy joint were investigated, and the interfacial metallurgical bonding state and micromorphology of the joints brazed at different temperatures were compared and analyzed. The results show that the prewelded joint fabricated with magnetic discharge voltage of 12 k V, pipe-to-pipe gap of 1.5 mm and filler metal slice＇s thickness of 150 μm has good appearance, pipes＇ fitting degree and bonding strength. The joint brazed at 420 ℃ for 5 s shows good interfacial bonding.Continuous element diffusion layer is formed on the bonding surfaces between the base metal and aluminum base metals, and there are no welding defects such as holes and cracks in the solder layer. The solder layer consists of α-Al proeutectic phase and fine homogeneous Zn-Al eutectic phase.