薄板铝合金VPPA平焊工艺.pdfVIP

母材相同，焊缝显微组织致密，无气孔夹杂等缺陷。 关键词：铝合金；变极性等离子弧；焊缝成形 Abstract Compared with other fusion welding, VPPA (Variable Polarity Plasma Arc) welding process has many advantages, such as concentrated energy, higher arc stiffness, more penetration as well as smaller deformation etc, which can realize the two-sided appearance welding by one side without groove. VPPA welding has succeeded applies the welding productions of outside storage of aerospace craft which has the widespread application prospect. In this paper, the welding source system comprises a Variable Polarity Plasma arc welding power source, wire feeder, semiautomatic welding tractor as well as hannover welding quality analyzer and so on in experimentation. The welding power source use double inverter technical, output constant-current. The first inverter control circuit through PWM and PFM in company with to control IGBT driving circuit of power source. The second inverter control core is microcontroller 80C196KC which output Variable Polarity current. The microcontroller 80C196KC procedure can independently adjust the positive and negative polarity electric current peak-to-peak value and the positive and negative polarity electric current time ratio separately. In this paper, the aluminum alloy thin steel plate was welding used by variable polarity plasma arc flat position welding technology. The influence which the welding parameters such as welding current, flux of plasma gas and wire feed rate etc to appearance of weld are analyzed. The welding current is Key aspect of the appearance o