(1. 華中科技大學(xué) 武漢光電國家實(shí)驗(yàn)室(籌)，武漢 430074；
2. 華中科技大學(xué) 光電子科學(xué)與工程學(xué)院，武漢 430074)
摘 要: 對8 mm厚2A12鋁合金板進(jìn)行CO2激光−MIG(metal inter gas)復(fù)合焊接，討論了焊接電壓和焊接速度對焊縫幾何參數(shù)的影響，并研究接頭顯微組織和力學(xué)性能。結(jié)果表明：熔深和母材熔化面積決定于焊接速度。隨著焊接電壓的降低，焊縫熔寬、堆高面積、焊縫固液趾角逐漸減小，而成形系數(shù)逐漸增加。接頭顯微組織由α(Al)基體及α(Al)+Al2Cu+Mg2Si三相共晶組成；接頭抗拉強(qiáng)度為281 MPa，為母材抗拉強(qiáng)度的69%；接頭拉伸斷口呈韌脆混合斷裂，而母材斷口呈微孔聚集型延性斷裂。
關(guān)鍵字: 鋁合金；復(fù)合焊接；焊縫幾何參數(shù)；顯微組織
（1. Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology,
Wuhan 430074, China
2. School of Optoelectronics Science and Engineering, Huazhong University of Science and Technology,
Wuhan 430074, China）
Abstract:The experiments of CO2 laser-metal inter gas (MIG) arc hybrid welding for 2A12 aluminum alloy with the thickness of 8 mm were carried out. The effects of arc voltage and welding speed on bead geometry parameters were discussed, and the microstructure and mechanical properties of joint were studied. The results show that the welding speed affects the bead penetration depth and bead penetration area. The bead width, bead reinforcement area and liquid-solid toe angle decrease with decreasing arc voltage, while the penetration shape factor increases with decreasing arc voltage. The microstructure of the joint is composed of α(Al) matrix and α(Al)+θ+Mg2Si eutectic. The tensile strength of the joint is 281 MPa, which is approximately 69% of base metal. The fracture surface morphology observation shows that the joint exists as brittle-ductile mixture fracture, while the base metal exists as microvoid accumulation fracture.
Key words: 2A12 aluminum alloy; hybrid welding; bead geometry parameter; microstructure
