摘要
Due to poor metallurgical weldability of magnesium alloy,laser welding crack is still one of the main defects.The generations of welding crack seriously affected the weld quality and reduce the mechanical properties of welded joints which have become a bottleneck of the magnesium alloy products widely used in the structure materials.In this paper,AZ31B magnesium alloy sheet with 2mm thickness was used for this investigation.The forming reason and extending characteristics of the welding cracks were investigated during the Nd:YAG pulsed laser welding.The results show that welding cracks are mainly solidification crack which were always present in the weld centers.Few welding hot cracks appear multiple furcation phenomenons,and main and branch cracks were intercrystalline crack.The partial branch crack was mixed intercrystalline and transgranular extension.In addition,few cracks in the weld were caused due to irregular shape porosity and inclusion.The delayed crack weren't observed in the weld after deposited 48 hours.In the pre-process on the basis,the characteristics and generation mechanism of YAG pulsed laser welding cracks of magnesium alloy were analyzed further.
Due to poor metallurgical weldability of magnesium alloy,laser welding crack is still one of the main defects.The generations of welding crack seriously affected the weld quality and reduce the mechanical properties of welded joints which have become a bottleneck of the magnesium alloy products widely used in the structure materials.In this paper,AZ31B magnesium alloy sheet with 2mm thickness was used for this investigation.The forming reason and extending characteristics of the welding cracks were investigated during the Nd:YAG pulsed laser welding.The results show that welding cracks are mainly solidification crack which were always present in the weld centers.Few welding hot cracks appear multiple furcation phenomenons,and main and branch cracks were intercrystalline crack.The partial branch crack was mixed intercrystalline and transgranular extension.In addition,few cracks in the weld were caused due to irregular shape porosity and inclusion.The delayed crack weren't observed in the weld after deposited 48 hours.In the pre-process on the basis,the characteristics and generation mechanism of YAG pulsed laser welding cracks of magnesium alloy were analyzed further.
作者
Cui Zeqin1,2,Wang Wenxian1,2,Si En1,Xu Bingshe1,21Key Laboratory of Interface Science and Engineering in Advanced Materials (Taiyuan University of Technology),Ministry of Education,Tai-yuan 030024,China2College of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2011年第S4期21-25,共5页
Rare Metal Materials and Engineering
基金
Foundation item:NSFC(51075293)
