(1. 重慶大學(xué) 材料科學(xué)與工程學(xué)院，重慶 400044；
2. 重慶市科學(xué)技術(shù)研究院，重慶 401123)
摘 要: 采用鎢極氬弧焊(TIG)方法對(duì)AZ31鎂合金進(jìn)行焊接實(shí)驗(yàn)，研究新型復(fù)合助焊劑對(duì)AZ31鎂合金焊接接頭組織的性能的影響，探索優(yōu)化鎂合金焊接質(zhì)量的方法和工藝。結(jié)果表明：實(shí)驗(yàn)所使用的新型助焊劑可通過(guò)“電弧收縮”和“表面張力”復(fù)合效應(yīng)來(lái)優(yōu)化焊接熱循環(huán)；部分助焊劑以原子態(tài)進(jìn)入電弧區(qū)域作用于焊接電弧，而熔入熔池的助焊劑則是通過(guò)改變?nèi)鄢乇砻鎻埩?lái)加大AZ31鎂合金焊接熔深，減小熔寬；助焊劑增加熔合區(qū)晶粒形核能力，細(xì)化該區(qū)晶粒，使第二相呈網(wǎng)狀分布，提高AZ31鎂合金焊接接頭的綜合力學(xué)性能。
關(guān)鍵字: AZ31鎂合金；新型復(fù)合助焊劑；焊接接頭；顯微組織
（1. College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China;
2. Chongqing Academy of Science and Technology, Chongqing 401123, China）
Abstract:GTAW (TIG) method was applied to the AZ31 magnesium alloy’s welding and the effects of new compound flux on the microstructure and properties of TIG welding of AZ31 magnesium alloy were investigated to develop new method and technology for promoting the quality of magnesium alloy welding. The results show that the new compound flux can optimize the welding thermal cycle through combining the arc-contraction effect and surface tension effect. Part of the flux runs into the arc region and acts on the welding arc. The melting flux into the pool increases the welding penetration of AZ31 magnesium and reduces the melting width by changing the surface tension of the molten pool significantly. The new flux increases fusion zone grain nucleation capacity, refines the grain, and makes the second phase distribute as network, which improves the mechanical properties of welded joints of AZ31 magnesium alloy.
Key words: AZ31 magnesium alloy; new compound flux; welded joints; microstructure
