不同频率下薄板铝合金VPPA穿孔成型及焊缝性能

Keyhole and Property of Aluminium Alloy Thin Sheet VPPA Welded Under Different AC Frequency

针对薄板铝合金穿孔型变极性等离子焊接控制困难的问题，探讨了交流频率对其焊接的影响规律，分析了交流频率在40及52Hz两种情况下，3mm厚的5A06铝合金VPPA焊接穿孔工艺特点。结果表明，采用合理的焊接参数，可以实现薄板铝合金的穿孔型变极性等离子焊接，并能够稳定地控制焊接过程。当交流频率增大时，焊漏宽度与焊漏高度均增大，咬边产生的几率减小，有利于薄板焊接。随着频率增大，热影响区与焊缝中心的弥散相有增大的趋势，但并不影响接头的拉伸性能。

In order to control the problem of aluminium alloy VPPA weld,the effect of AC frequency on VPPA welded 3 mm thickness aluminium alloy was investigated. The characteristics of keyholes at different AC frequency of 40 Hz and 52 Hz were analysed. The results show that the width and height of root reinforcement increasing with the increase of AC frequeny, which is advantageous to thin sheet welding. Enhancement of AC frequeny made the dispersed phase in weld and HAZ grown up. But the tensile strength is unaffected. The tensile strength of VPPA welded joint is between 370 and 380 MPa, which is even-matched welded joint.