Keyhole formation and its characteristics in laser welding mode transition  

作　　者：秦国梁 高进强 林尚扬 

机构地区：[1]Institute of Materials Joining, Shandong University, Jinan, 250061 [2]Harbin Welding Institute, Harbin, 150080.

出　　处：《China Welding》2010年第4期11-14,共4页中国焊接（英文版）

基　　金：Supported by National Natural Science Foundation of China （ Grant No. 50905099 ） and the Joint Foundation of the National Natural Science Foundation of China and China Academy of Engineering Physics （Grant No. 10776020）.

摘　　要：Keyhole is the most important characteristic for laser deep penetration welding, and its formation indicates the beginning of laser deep penetration welding mode. The keyhole developing process was analyzed and the keyhole formation time was calculated according to welding speed and the length of weld bead formed in the keyhole formation process. The results showed that the keyhole forms in 40 -70 ms at different rate of change of laser power. In laser deep penetration welding process, the variation of light intensity radiated by laser induced plasma can identify the keyhole formation, but it can not be used to estimate the keyhole formation time because of delay effect.Keyhole is the most important characteristic for laser deep penetration welding, and its formation indicates the beginning of laser deep penetration welding mode. The keyhole developing process was analyzed and the keyhole formation time was calculated according to welding speed and the length of weld bead formed in the keyhole formation process. The results showed that the keyhole forms in 40 -70 ms at different rate of change of laser power. In laser deep penetration welding process, the variation of light intensity radiated by laser induced plasma can identify the keyhole formation, but it can not be used to estimate the keyhole formation time because of delay effect.

关 键 词：laser welding mode transition keyhole formation laser induced plasma 

分 类 号：TG456.7[金属学及工艺—焊接] U213.6[交通运输工程—道路与铁道工程]