Microstructure and mechanical properties of welds of AZ31B magnesium alloy produced by different gas tungsten arc welding variants  

作　　者：S.Srinivasan R.Ravi Bharath A.Atrens P.Bala Srinivasan 

机构地区：[1]School of Mechanical Engineering,SASTRA Deemed to be University,Thanjavur 613401,India [2]Welding Research Institute,Bharat Heavy Electricals Limited,Tiruchirappalli 620014,India [3]School of Mechanical and Mining Engineering,Centre for Advanced Materials Processing and Manufacturing(AMPAM),University of Queensland,St Lucia,QLD 4072,Australia [4]High Energy Batteries(India)Limited,Mathur,Tiruchirappalli 622515,India

出　　处：《Defence Technology(防务技术)》2025年第2期98-110,共13页Defence Technology

摘　　要：This work aimed to(i)understand conventional and pulse gas tungsten arc welding(GTAW)of AZ31B,and(ii)explore high frequency welding(100 Hz-1500 Hz).GTA welding with alternating current(AC)and direct current electrode positive(DCEP)polarities yielded crack-free partial penetration welds for6 mm thick AZ31B alloy sheet.Welding under direct current electrode negative(DCEN)polarity with identical parameters as that for AC and DCEP resulted in full penetration welds that had microcracks.Defect-free full-penetration welds could be accomplished with pulse GTA welding using DCEN polarity at a pulse frequency of 1 Hz with a pulse duration ratio of 1:1.The resultant DCEN P 1:1 weld metal had a microstructure finer than the conventional DCEN weld.Welds produced with pulse duration ratios of 1:2and 1:4 lacked penetration but had a much finer microstructures because of the lower heat input.The arc constriction by the high frequency pulsing in the Activ Arc■-High frequency(AA-HF)mode welding was responsible for deeper penetration.Welds produced under DCEN pulsing and AA-HF conditions had hardness higher than conventional DCEN,DCEP and AC GTA welds,attributed to the finer microstructure.AA-HF GTA welding produced defect free deeper penetration welds with good microstructural features/mechanical properties and also gave an advantage of 50%enhanced productivity when welded at1500 Hz.

关 键 词：AZ31B alloy Pulse GTAW High frequency Microstructure Mechanical properties PRODUCTIVITY 

分 类 号：TG1[金属学及工艺—金属学]