基于光纤激光的LY12铝合金焊接试验分析

Welding of LY12 aluminum alloy based on fibre laser

关键词:  激光技术  激光焊接  LY12铝合金  焊接工艺  组织性能

Key words:  laser technique  laser welding  LY12 aluminum alloy  welding process  microstructure and property

摘要:

在飞机制造领域，铝合金主要用于制造飞机蒙皮、梁、桁条和框架等结构.采用多模光纤激光器进行了1.4 mm厚LY12铝合金的激光焊接试验，研究了焊接工艺参数对铝合金焊缝形貌的影响规律，并对焊接接头的显微硬度及断口形貌进行了分析.结果表明，大功率高速度连续激光焊缝的成形具有不稳定性，当功率为2 200 W，焊接速度为55 mm/s，保护气体流量为10 L/min时，可以获得成形良好且无宏观缺陷的焊接接头.接头的平均抗拉强度约为388 MPa，达到母材抗拉强度的63.98%，断裂类型为韧脆混合型断裂.

Abstract:

In aircraft manufacturing industry, the aluminum alloy is mainly used in the skin, beam, purlin and frame structures. Laser welding of 1.2 mm thick LY12 aluminum alloy sheets was conducted with multimode fibre laser. The influence of laser welding parameters on aluminum alloy weld shape was studied, and the fracture appearance and microhardness of welded joint were analyzed. The results show that the weld appearance with large power and high speed continuous laser was instable. The welded joint with good shape and free defects can be obtained with laser power of 2 200 W, welding speed of 55 mm/s and shielding gas flow rate of 10 L/min. The average tensile strength of joint was 388 MPa, reaching 63.98% of that of the base metal. The fracture of the joint was a mixed ductile brittle mode.