Microstructure Evolution and Recrystallization Behavior of Friction Stir Welded Thick Al-Mg-Zn-Cu alloys: Influence of Pin Centerline Deviation
Microstructure Evolution and Recrystallization Behavior of Friction Stir Welded Thick Al-Mg-Zn-Cu alloys: Influence of Pin Centerline Deviation
复制标题
搅拌摩擦焊厚Al-Mg-Zn-Cu合金的显微组织演变和再结晶行为：销轴中心线偏差的影响
DOI：
10.1007/s40195-021-01307-0
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发表时间：
2021-09-07
影响因子：
3.5
通讯作者：
Chen, Yu-Hua
中科院分区：
文献类型：
--
作者：
Mao, Yu-Qing;Yang, Ping;Chen, Yu-Hua
采用四种不同的搅拌头中心线偏差对铝镁锌铜合金厚板进行搅拌摩擦焊试验。结果表明，与无中心偏差的销相比，中心偏差的销由于温度升高和偏心力增大，有利于改善塑性材料的流动性，增大焊核区尺寸，细化晶粒和再析出相颗粒，提高动态再结晶程度和大角度晶界数量，导致应变硬化的增加。特别是中心线偏差为0.2 mm的旧销，其厚接头的平均硬度和冶金性能最高，这与显微组织演变和再结晶行为相一致。中心线偏离0 ~ 0.3mm的钉头接头的断裂模式由焊核区的脆性断裂逐渐转变为热影响区的韧性断裂。
Four tools with different pin centerline deviations were fabricated to friction stir weld (FSW) thick plates of Al-Mg-Zn-Cu alloys. The results show that, compared with the pin without pin centerline deviation, the applying of pin centerline deviation is favorable to improve the flowability of plastic material, enlarging the size of nugget zone, refining the grains and reprecipitated phase particles, enhancing the degrees of dynamic recrystallization and quantity of high angle grain boundaries owing to higher temperature and bigger eccentric force, resulting in the increase of strain hardening. Especially for the used pin with a centerline deviation of 0.2 mm, the highest average hardness and best metallurgical properties of thick FSW joints are produced, and which are consistent with the microstructure evolution and recrystallization behavior. Moreover, the fracture mode of the joints produced by the pins with centerline deviation from 0 mm to 0.3 mm changes gradually from a brittle fracture in the nugget zone (NZ) to a ductile failure in the HAZ.