Citation: | JIANG Fan, FANG Shitong, ZHANG Guokai, CHEN Shujun, LI Tianming, XU Bin. Front-side monitoring technology for back-side keyhole state in VPPAW[J]. TRANSACTIONS OF THE CHINA WELDING INSTITUTION, 2025, 46(1): 8-14. DOI: 10.12073/j.hjxb.20231107002 |
In the process of variable polarity plasma arc welding (VPPAW), the state of the keyhole, particularly the back-side keyhole, was a critical factor influencing the weld formation quality. However, in practical welding operations, monitoring the keyhole state from the backside with sensors presented significant challenges. Therefore, this paper proposed a method for detecting the back-side keyhole on the front view using plasma arc welding based on the reflection from the front wall of the molten pool. With appropriate shooting angles, this method could simultaneously capture both the front-side keyhole images and the reflected shape of the back-side keyhole on the front wall. The relationship between the welding quality and the reflective shape of the keyhole was established through experiments at different welding currents. With the increase of welding current, the position of the detected keyhole image on the front wall was gradually shifted upward. When the weld appeared to be cut, the reflective shape of the keyhole on the back disappeared; when the stable weld state was disturbed, the reflective shape of the keyhole on the back changed at the same time. The stability of the keyhole was directly related to the stability of the welding states. The reflective shape of the backside keyhole on the front wall was affected by the welding state and the molten pool state. This provided important guidance for establishing the correlation between the reflective shape of the keyhole on the back and the welding quality.
[1] |
王小伟, 张斌, 曾如川, 等. 铝合金VPPAW穿孔焊接匙孔闭合处的微观组织与力学性能[J]. 焊接学报, 2024, 45(3): 1 − 6. doi: 10.12073/j.hjxb.20230402001
Wang Xiaowei, Zhang Bin, Zeng Ruchuan, et al. Microstructure and mechanical properties of welds at keyhole closures in variable-polarity plasma arc welding of Al alloy[J]. Transactions of the China Welding Institution, 2024, 45(3): 1 − 6. doi: 10.12073/j.hjxb.20230402001
|
[2] |
韩蛟, 韩永全, 洪海涛, 等. 基于光谱诊断的VPPA-MIG复合电弧耦合机理分析[J]. 焊接学报, 2023, 44(11): 104 − 109. doi: 10.12073/j.hjxb.20221211001
Han Jiao, Han Yongquan, Hong Haitao, et al. Analysis of VPPA-MIG hybrid arc coupling mechanism based on spectral diagnosis[J]. Transactions of the China Welding Institution, 2023, 44(11): 104 − 109. doi: 10.12073/j.hjxb.20221211001
|
[3] |
Jiao W H, Wang Q Y, Cheng Y C, et al. End-to-end prediction of weld penetration: a deep learning and transfer learning based method[J]. Journal of Manufacturing Processes, 2021, 63: 191 − 197. doi: 10.1016/j.jmapro.2020.01.044
|
[4] |
Zhou F Z, Liu X F, Zhang X F, et al. Keyhole status prediction based on voting ensemble convolutional neural networks and visualization by grad-CAM in PAW[J]. Journal of Manufacturing Processes, 2022, 80: 805 − 815. doi: 10.1016/j.jmapro.2022.06.034
|
[5] |
Nomura K, Fukushima K, Matsumura T, et al. Burn-through prediction and weld depth estimation by deep learning model monitoring the molten pool in gas metal arc welding with gap fluctuation[J]. Journal of Manufacturing Processes, 2021, 61: 590 − 600. doi: 10.1016/j.jmapro.2020.10.019
|
[6] |
陈宸, 周方正, 李成龙, 等. 融合空间和通道特征的等离子弧焊熔池熔透状态预测方法[J]. 焊接学报, 2023, 44(4): 30 − 38. doi: 10.12073/j.hjxb.20220516001
Chen Chen, Zhou Fangzheng, Li Chenglong, et al. Prediction method of plasma arc welding molten pool melting state based on spatial and channel characteristics[J]. Transactions of the China Welding Institution, 2023, 44(4): 30 − 38. doi: 10.12073/j.hjxb.20220516001
|
[7] |
Kim H, Nam K, Oh S, et al. Deep-learning-based real-time monitoring of full-penetration laser keyhole welding by using the synchronized coaxial observation method[J]. Journal of Manufacturing Processes, 2021, 68: 1018 − 1030. doi: 10.1016/j.jmapro.2021.06.029
|
[8] |
Kim H, Nam K, Kim Y, et al. Analysis of laser-beam absorptance and keyhole behavior during laser keyhole welding of aluminum alloy using a deep-learning-based monitoring system[J]. Journal of Manufacturing Processes, 2022, 80: 75 − 86. doi: 10.1016/j.jmapro.2022.05.044
|
[9] |
樊重建. 变间隙铝合金脉冲GTAW熔池视觉特征获取及其智能控制研究[D]. 上海: 上海交通大学, 2008.
Fan Chongjian. Weld pool characters extraction visual sensing and intelligent control during varied gap aluminum alloy pulsed GTAW process[D] Shanghai: Shanghai Jiao Tong University, 2008.
|
[10] |
吴頔. 基于多源信息融合的铝合金VPPAW成形预测和智能控制研究[D]. 上海: 上海交通大学, 2018.
Wu Di. Research on predicting and intelligent control for weld formation during VPPAW process using multi-information fusion[D] Shanghai: Shanghai Jiao Tong University, 2018.
|
[11] |
Liu Z M, Wu C S, Cui S L, et al. Correlation of keyhole exit deviation distance and weld pool thermo-state in plasma arc welding process[J]. International Journal of Heat and Mass Transfer, 2017, 104: 310 − 317. doi: 10.1016/j.ijheatmasstransfer.2016.08.069
|
[12] |
Liu Z M, Wu C S, Chen M A. Experimental sensing of the keyhole exit deviation from the torch axis in plasma arc welding[J]. The International Journal of Advanced Manufacturing Technology, 2014, 71(3): 1209 − 1219.
|
[1] | HU Ruoqi, ZHANG Junjie, WANG Ying, ZHANG Dongxue, MU Ruijie, YANG Zhenwen. Microstructure and mechanical properties of 6063 Al alloy joints with AlSiMgCu brazing alloy by liquid phase-assisted diffusion bonding[J]. TRANSACTIONS OF THE CHINA WELDING INSTITUTION, 2025, 46(6): 11-19. DOI: 10.12073/j.hjxb.20240320002 |
[2] | TAO Jun, HOU Jinbao, JIANG Bangzheng, YANG Zhaoxi, CHEN Xiukai. Effect of SiC powder ratio on interfacial microstructure and mechanical property of CMC /superalloy brazing joint[J]. TRANSACTIONS OF THE CHINA WELDING INSTITUTION, 2025, 46(2): 87-94. DOI: 10.12073/j.hjxb.20240908002 |
[3] | WANG Xujian, TAN Caiwang, HE Ping, FAN Chenglei, GUO Dizhou, DONG Haiyi. Microstructure and mechanical properties of CuCrZr /Inconel 625 laser welding joints on HEPS storage ring vacuum box[J]. TRANSACTIONS OF THE CHINA WELDING INSTITUTION, 2023, 44(6): 35-40. DOI: 10.12073/j.hjxb.20220204002 |
[4] | Wang Xujian, Tan Caiwang, Dong Haiyi, He Ping, Fan Chenglei, Guo Dizhou. Microstructure and mechanical properties of CuCrZr /316LN laser welding joints on HEPS thin wall vacuum box[J]. TRANSACTIONS OF THE CHINA WELDING INSTITUTION. DOI: 10.12073/j.hjxb.20220414001 |
[5] | LI Xiaoqiang, LOU Li, QU Shengguan, YANG Chao, LI Li. Microstructure and properties of brazing joints with a Ti-based filler of TiAl/GH536 alloy[J]. TRANSACTIONS OF THE CHINA WELDING INSTITUTION, 2019, 40(10): 80-85. DOI: 10.12073/j.hjxb.2019400267 |
[6] | SONG Xiaoguo1,2, SI Xiaoqing1,2, NI Haochen2, CAO Jian1, YU Jinbo2, FENG Jicai1. Interfacial microstructure and properties of TiAl alloy brazed joint with Ni-34Ti brazing alloy[J]. TRANSACTIONS OF THE CHINA WELDING INSTITUTION, 2017, 38(7): 13-16. DOI: 10.12073/j.hjxb.20150723002 |
[7] | XU Xiaolong, LI Zhuoran, LIU Ruihua, WANG Zhengzheng. Microstructure and mechanical properties of ZrB2-SiC ceramic composite brazed joint[J]. TRANSACTIONS OF THE CHINA WELDING INSTITUTION, 2014, 35(1): 59-62. |
[8] | SONG Xiaoguo, CAO Jian, CHEN Haiyan, SI Guodong, FENG Jicai. Interfacial microstructure and properties of TiAl joints brazed with composite filler reinforced by particles[J]. TRANSACTIONS OF THE CHINA WELDING INSTITUTION, 2013, (7): 13-16. |
[9] | LI Zhuoran, XU Xiaolong, LIU Wenbo, LU Zhiguo. Effect of joint clearances on microstructure and property of brazed SiC ceramics[J]. TRANSACTIONS OF THE CHINA WELDING INSTITUTION, 2012, (11): 9-12. |
[10] | YANG Zhenwen, ZHANG Lixia, LIU Yuzhang, HE Peng. Microstructure and mechanical property of vacuum brazed TiAl and C/SiC joint[J]. TRANSACTIONS OF THE CHINA WELDING INSTITUTION, 2011, (3): 65-68. |