对10 mm厚7075铝合金板材进行脉冲变极性等离子弧焊，研究了焊接电流和离子气流量的变化对焊缝成形系数的影响规律，确定了较优的焊接参数并获得了成形良好的焊缝，对该焊接接头力学性能进行分析. 结果表明，焊缝成形系数随着焊接电流的增大先减小后增大，随着离子气流量增大逐渐减小，较佳的焊缝成形系数区间为1.1 ~ 1.3，焊接电流比离子气流量对焊缝成形的影响更大. 当脉冲焊接电流为250 A/290 A，离子气流量为2.0 L/min时焊缝形貌较佳，接头焊缝区为树枝状晶，焊缝处的抗拉强度为397.9 MPa，约为母材的67.5%，焊缝的性能较好.
The welding process of 7075 aluminum alloy with a thickness of 10mm was carried out by PVPPAW. The influence of welding current and plasma gas flow rate on weld forming coefficient was studied. The optimum welding parameters were determined and the well-formed welds were obtained. The mechanical properties of the well-formed welded joints were analyzed. The results shown that the weld forming coefficient initially decreased and then increased with the increase of welding current. While the plasma gas flow rate increased, the weld forming coefficient gradually decreased. The better weld forming coefficient range is 1.1~1.3. Compared with the plasma gas flow rate, the welding current has greater influence on weld formation. The satisfying weld appearance can be achieved under the pulse welding current of 250 A/290 A, the plasma gas flow rate of 2.0 L/min. The welding quality is good under the optimum welding parameters, and the tensile strength of the weld reached 397.9 MPa, which is nearly 67.5% of that of the base metal. The weld area exhibited the dendrite microstructure.
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