7050-T7451铝合金搅拌摩擦焊组织及性能分析
Microstructure and Mechanical Properties of7050-T7451 Aluminum Welded by Friction Stir
付春坤, 白 钢, 胡亚真, 苏利龙
点击：3673次 下载：0次
作者单位：（西北工业大学 陕西省摩擦焊接重点实验室,陕西 西安 710072）
中文关键字： 搅拌摩擦焊;铝合金;微观组织;力学性能
英文关键字： friction stir welding; aluminum alloy; microstructure; mechanical property
中文摘要：在不同的焊接工艺参数下对8 mm厚的7050-T7451铝合金板进行了搅拌摩擦焊接实验。通过对焊接接头组织的分析,发现焊核区晶粒为明显的细化再结晶等轴晶；热机影响区晶粒沿流线方向拉长且有细小沉淀相在晶界上析出；热影响区的组织发生了晶粒粗化。沿焊缝横截面的显微硬度分布呈高-低-高-低-高的趋势,硬度最低处位于后退侧的热影响区。实验结果表明,在旋转速度为375 r/min、焊接速度为100 mm/min时,可以获得较好的焊缝组织,抗拉强度达到了452 MPa。
英文摘要：7050-T7451 aluminum alloy with 8 mm thickness was welded in friction stir welding at different welding parameters. The microstructure of the welded joints was studied by optical microscopy. It is found that the weld nugget has a dynamic recrystallization, fine isometric crystal structure. The grains are elongated along deformation lines and small precipitations occur in grain boundary of the TMAZ. The size of grains in the HAZ is large. The distribution of microhardness in the cross section presents a trend of high-low-high-low-high, the lowest hardness is in the advancing side of the HAZ. The experiment results shows,when the rotating speed is 375 r/ min and the welding speed is 100 mm/ min,the good weld is achieved and the tensile strength of the weld seam reaches 452 MPa.