中文摘要：

为了研究变极性脉冲熔化极惰性气体保护焊在焊核薄板时焊丝的受热机理以及熔滴过渡时的电弧形态与 受力过程,搭建了熔滴过渡过程与焊接电信号的同步采集实验平台,对应分析了焊接电流与熔滴长大及脱落过程,得到了电流波形与熔滴过渡状态的匹配关系. 通过分析不同阶段熔滴受力状态及其对熔滴过渡的影响,得到了固 定频率条件下各阶段的时间配比对熔滴过渡形态的影响. 通过调节工艺参数实现了一脉一滴的熔滴过渡过程,得 到了均匀稳定的焊缝. 分析了熔滴脱落形态,研究了熔滴各特征尺寸. 结果表明电信号不同波段持续时间对熔滴 尺寸有明显影响.

英文摘要：

To study the heating mechanism of the welding wire and the arc shape and stress process during the dreplet tranfer in variable polarity pulsed MIG welding, an experimental platform was established to measure the images of droplet transfer and electrical signal synchronously. To obtain the relationship of current waveform and the shape of droplet, the weld current and droplet transfer were analyzed correspondingly. With the fixed frequency ratio, the effect of time ratio to droplet transfer was obtained by analyzing the driving force of droplet at different current stages. A pulse of a drop of molten drops transfer process was achieved by adjusting the process parameters and then the uniform and stable welding seam was obtained. Studying feature sizes of the molten drops by analyzing the drop off form and the results shows that the electrical signal duration of different bands have obvious effects on droplet size.