CAJ | 학술논문

研制基于单片机控制的具有高低频调制脉冲功能的双逆变变极性等离子弧(Variable polarity plasma arc，VPPA)焊接系统，检测并分析叠加不同高低频脉冲参数条件下该焊接系统输出信号的特征，并对系统进行实际焊接试验，结果表明系统运行良好。从特征信号的时域及频域分析发现，当高频脉冲频率提高到2 kHz时，与1 kHz相比较，脉冲上下降沿斜率降低1.2倍，高次谐波量增加1.4倍。由焊接试验结果得出，当高频脉冲频率及正反极性电流等工艺参数选择合适时，可以得到比典型VPPA焊接更加优越的焊缝成形，获得具有均匀鱼鳞纹的理想焊缝。从焊缝显微组织的分析发现，脉冲VPPA焊接工艺得到的焊缝晶粒比典型VPPA焊缝晶粒细小，因此该焊接工艺对进一步提高航空航天高强铝合金焊接质量具有重要意义。
연제기우단편궤공제적구유고저빈조제맥충공능적쌍역변변겁성등리자호(Variable polarity plasma arc，VPPA)한접계통，검측병분석첩가불동고저빈맥충삼수조건하해한접계통수출신호적특정，병대계통진행실제한접시험，결과표명계통운행량호。종특정신호적시역급빈역분석발현，당고빈맥충빈솔제고도2 kHz시，여1 kHz상비교，맥충상하강연사솔강저1.2배，고차해파량증가1.4배。유한접시험결과득출，당고빈맥충빈솔급정반겁성전류등공예삼수선택합괄시，가이득도비전형VPPA한접경가우월적한봉성형，획득구유균균어린문적이상한봉。종한봉현미조직적분석발현，맥충VPPA한접공예득도적한봉정립비전형VPPA한봉정립세소，인차해한접공예대진일보제고항공항천고강려합금한접질량구유중요의의。
A double-inverter variable polarity plasma arc(VPPA) welding system with high-low frequency modulation, controlled by single chip microcomputer is introduced and its characteristics of output signal with different conditions of adding high-low frequency pulse are tested and analyzed. Its welding test is performed and the results show the system runs well. It is analyzed from the time and frequency domain of the characteristic signals that compare with 1 kHz, when pulse frequency increases to 2 kHz the slope of pulse reduces 1.2 times and higher harmonic increases 1.4 times. The welding experiment results show that it can get better welding gap than typical VPPA welding and obtain uniform ripple welding line when process parameters including high frequency pulse, positive and negative polarity currents etc. are chosen appropriately. After examination of the weld microstructure, it is found that the pulse VPPA could obtain finer weld grains than typical VPPA. Because of improving quality of welding, the welding procedure is significant for high-intensity Al-alloy welding in aerospace.