Microstructure Evolution and Mechanical Properties of High-Speed Friction Stir Welded Aluminum Alloy Thin Plate Joints
Microstructure Evolution and Mechanical Properties of High-Speed Friction Stir Welded Aluminum Alloy Thin Plate Joints
复制标题
高速搅拌摩擦焊铝合金薄板接头组织演变及力学性能
DOI：
10.1007/s11665-018-3441-4
复制
发表时间：
2018-07-01
影响因子：
2.3
通讯作者：
Chen, Haiyan
中科院分区：
文献类型：
--
作者：
Liu, Fenjun;Fu, Li;Chen, Haiyan
在常规转速（2000 rpm, 300 mm/min）和高速转速（11000 rpm, 1500 mm/min）下，获得了0.8 mm厚6061-T6铝合金板的搅拌摩擦焊接（FSW）接头。对其再结晶机理、析出相演化、力学性能和断裂行为进行了详细的研究。显微组织分析表明，熔核区（NZ）的晶粒结构演变以连续动态再结晶为主。在FSW过程中，与常规速度相比，高速有助于形成更细的等轴再结晶晶粒，更高的位错和亚结构密度，以及更多的NZ析出相，从而进一步显著提高了接头的硬度和抗拉强度。最大抗拉强度为292.6 MPa， 6061-T6铝合金的抗拉强度为83.2%，常规速度FSW接头的抗拉强度为122.6%。本工作为制备具有优良力学性能的FSW铝合金薄板接头提供了有效的方法。
Sound friction stir welded (FSW) joints of 6061-T6 aluminum alloy sheets with an 0.8 mm thickness were obtained at conventional speed (2000 rpm, 300 mm/min) and high speed (11,000 rpm, 1500 mm/min). The recrystallization mechanism, precipitate evolution, mechanical properties and fracture behavior were investigated in detail. Microstructure analyses revealed that the grain structure evolution in the nugget zone (NZ) was dominated by continuous dynamic recrystallization. In the process of FSW, high speed facilitates the formation of finer equiaxed recrystallized grains, higher density of dislocations and substructures, and a larger number of precipitates in the NZ compared to the conventional speed, which further significantly improves the hardness and tensile strength of the joints. The maximum tensile strength was obtained with 292.6 MPa, 83.2% for the 6061-T6 aluminum alloy and 122.6% for the conventional-speed FSW joints. This work provides an effective method for preparing FSW aluminum alloy thin plate joints with excellent mechanical properties.