A7N01P-T4铝合金激光-MIG复合焊接头微区性能

Micro-zone performance of laser-MIG hybrid welded A7N01P-T4 Al alloy joints

摘要: 以高速列车用14 mm A7N01P-T4铝合金为研究对象，对其激光-MIG复合焊接头的焊缝（WM）、热影响区（HAZ）两个微区以及母材（BM）进行微区拉伸、断裂韧度等性能测试，并结合金相、断口扫描等分析该种接头各区及母材的性能差异.结果表明，A7N01P-T4铝合金母材的抗拉强度最高，其次为激光-MIG复合焊接头热影响区，焊缝最差；接头热影响区的断裂韧度J_m_（14）值最高，约为119.580 kJ/mm²，其抵抗裂纹扩展的能力是3个区域中最强的；Shapiro-Wilk正态性检验表明，A7N01P-T4铝合金激光-MIG复合焊接头的断裂韧度测试结果具有较高的可靠性.

Abstract: Laser-MIG hybrid welded joint of 14mm A7N01P-T4 Al alloy for high speed train was investigated, the properties of WM (weldmetal), HAZ (heat affect zone) of joints and BM (base metal) were tested respectively, such as micro-zone tensile property, fracture toughness and so on, and the differences of micro-zone properties were analyzed by OM and SEM. BM has the best micro-zone tensile strength, while that of WM is the lowest. HAZ has the highest fracture toughness Jm(14), which can reach up to 119.580 kJ/mm² and indicatesan outstanding ability to resist crack growth in hybrid welded joints. Shapiro-Wilk normality test showed that fracture toughness of laser-MIG hybrid welded A7N01P-T4 Al alloy joints is extremely reliable.