Elyasi Majid, Taherian Javad, Hosseinzadeh Morteza, Kubit Andrzej, Derazkola Hamed Aghajani
Department of Mechanical Engineering, Noushiravani University of Technology, Babol, Iran.
Department of Mechanical Engineering, Islamic Azad University of Sari Branch, Sari, Iran.
Heliyon. 2023 Mar 23;9(4):e14752. doi: 10.1016/j.heliyon.2023.e14752. eCollection 2023 Apr.
This study investigated the effects of friction stir welding thread on the quality of dissimilar joints between AA6068 aluminum alloy and copper. The developed computational fluid dynamic (CFD) method was employed to simulate the tool's heat generation and thermo-mechanical action. The materials flow, microstructure, mechanical properties, and hardness of joints were assessed. The results indicated that the threaded pin increased heat generation during welding. The maximum temperature recorded on the aluminum side was 780 K for the cylindrical joint and 820 K for the threaded pin joint. The size of the stir zone in the threaded pin joint was bigger than the cylindrical pin. On the other hand, mechanical interlocking between AA6068 aluminum alloy and copper increased in the threaded pin joint. The material's velocity and strain rate increased by the higher stirring action of the threaded tool. Higher strain rate and materials velocity decreased microstructure size in the stir zone. The experimental result shows that the ultimate tensile strength of the cylindrical pin joint was 272 MPa, and the threaded pin joint was 345 MPa. The average microhardness of the cylindrical pin joint was near 104 H V, and for the threaded pin was 109 H V. The results show that the ultimate tensile strength and hardness of threaded pin joint increases by 25% and 5% in comparing cylindrical pin joint.
本研究调查了搅拌摩擦焊螺纹销对AA6068铝合金与铜异种接头质量的影响。采用所开发的计算流体动力学（CFD）方法来模拟工具的发热和热机械作用。对接头的材料流动、微观结构、力学性能和硬度进行了评估。结果表明，螺纹销在焊接过程中增加了热量的产生。圆柱形接头铝侧记录的最高温度为780K，螺纹销接头为820K。螺纹销接头中搅拌区的尺寸比圆柱形销的大。另一方面，螺纹销接头中AA6068铝合金与铜之间的机械互锁增加。螺纹工具更高的搅拌作用提高了材料的速度和应变率。更高的应变率和材料速度减小了搅拌区的微观结构尺寸。实验结果表明，圆柱形销接头的极限抗拉强度为272MPa，螺纹销接头为345MPa。圆柱形销接头的平均显微硬度接近104HV，螺纹销的为109HV。结果表明，与圆柱形销接头相比，螺纹销接头的极限抗拉强度和硬度分别提高了25%和5%。
