Effect of welding parameters on microstructure and mechanical properties of friction stir welded joints of 2060 aluminum lithium alloy
Effect of welding parameters on microstructure and mechanical properties of friction stir welded joints of 2060 aluminum lithium alloy
复制标题
焊接参数对2060铝锂合金搅拌摩擦焊接头组织及力学性能的影响
DOI：
10.1007/s00170-015-7191-2
复制
发表时间：
2015-11-01
影响因子：
3.4
通讯作者：
Liu, Qiang
中科院分区：
文献类型：
--
作者：
Mao, Yuqing;Ke, Liming;Liu, Qiang
在95 ~ 150mm /min的焊接速度和750 ~ 1500rpm的转速下，对2 mm厚的2060铝锂合金板进行搅拌摩擦焊接。研究了焊接速度和转速对接头成形质量、组织、二次相颗粒相变和力学性能的影响。结果表明：不同搅拌摩擦焊参数均可产生无缺陷接头，且随着转速的增加或焊接速度的降低，熔核尺寸先增大后减小；焊接熔核区具有细小的动态再结晶晶粒，当转速增加到1180转/分或焊接速度降低到118毫米/分时，晶粒尺寸减小到7.9 μ m，而当转速增加到1500转/分或焊接速度降低到95毫米/分时，晶粒粗化。二次相颗粒的转变也有类似的趋势，在1180 rpm-118 mm/min时，WNZ中二次相颗粒的尺寸最小。所有接头在硬度最低的地方都有软化区，接头断裂是由WNZs或热影响区引起的。在1180rpm ~ 118mm /min的焊接速度下，焊接接头的抗拉强度为495mpa，屈服强度为380mpa，伸长率为10.2%。随着转速的增加或焊接速度的降低，接头的强度和伸长率先增大后减小。
Two-millimeter-thick 2060 Al-Li alloy plates were friction stir welded under a welding speed of 95-150 mm/min and rotation speed of 750-1500 rpm. The effects of welding speed and rotation speed on formation quality, microstructure, secondary phase particles' transformation, and mechanical properties of the joints were investigated. The results show that defect-free joints are produced for varying friction stir welding (FSW) parameters, and nugget size increases firstly and then decreases with increasing rotation speed or decreasing welding speed. The weld nugget zones (WNZs) have fine dynamically recrystallized grains, and the size decreases to 7.9 mu m with increasing rotation speed to 1180 rpm or decreasing welding speed to 118 mm/min, while the grains are coarsened at 1500 rpm or 95 mm/min. A similar trend occurs in the transformation of secondary phase particles, whose size is the smallest in WNZ at 1180 rpm-118 mm/min. All joints exhibit softened zones where the hardness is the lowest, and the joints fracture from WNZs or heat-affected zones. The joints welded at 1180 rpm-118 mm/min perform the highest ultimate tensile strength of 495 MPa, yield strength of 380 MPa, and elongation of 10.2 %. With increasing rotation speed or decreasing welding speed, the strengths and elongation of the joints increase firstly and then decrease.