LF6铝合金与不锈钢异种金属惯性摩擦焊工艺技术研究

铝合金与不锈钢物理化学性能较大的差异使两者采用常规焊接技术较难实现连接。本文采用惯性摩擦焊接技术进行了LF6铝合金与不锈钢异种金属连接,分析研究了接头的微观组织及拉伸力学性能。研究结果表明,LF6铝合金与不锈钢惯性摩擦焊接过程中,相对不锈钢一侧,LF6铝合金一侧发生了较大的塑性变形,飞边主要由LF6铝合金摩擦挤压而成;微观组织显示LF6铝合金一侧分为细晶区、拉长晶区和母材区,细晶区中呈现为细小等轴晶状组织,拉长晶区为摩擦剪应力作用下的板条状拉伸组织。EDX分析表明,在摩擦热和顶锻力的作用下,焊接界面存在明显的浓度梯度,形成了数微米的扩散反应层;力学断口断裂于铝合金一侧受力薄弱区。

Inertia Friction Welding Between LF6 Aluminum Alloy and Stainless Steel

The welding between aluminum alloy and stainless steel is of practical importance for widening the application of aluminum alloys, however, it is difficult to join them using the conventional welding method because of their different physical and metallurgical properties. In this work, inertia friction welding has been used to create joints between LF6 aluminum alloy and stainless steel, and the microstructure and the mechanical properties were analyzed. The results showed that the flash of the joints was mainly caused by friction and extrusion of aluminum alloy during welding, and the microstructure in aluminum alloy side was divided into fine-grain and elongated-grain area. The EDX results displayed that the welded joint was of evident concentration gradient, and a very narrow interface diffusion layer was formed under the function of friction heat and upset force. The fracture mechanics model showed the fracture occurs at the weak area of aluminum alloy side.