Effects of initial microstructure on hot deformation behavior of Al-7.9Zn-2.7Mg-2.0Cu (wt%) alloy
Effects of initial microstructure on hot deformation behavior of Al-7.9Zn-2.7Mg-2.0Cu (wt%) alloy
复制标题
DOI：
10.1016/j.matchar.2019.03.019
复制
发表时间：
2019-05
影响因子：
4.7
通讯作者：
Q. Zang;Huashun Yu;Y. Lee;Minseok Kim;Hyoung-Wook Kim
中科院分区：
文献类型：
--
作者：
Q. Zang;Huashun Yu;Y. Lee;Minseok Kim;Hyoung-Wook Kim
在热变形前对Al-7.9Zn-2.7Mg-2.0Cu合金进行均匀化（470 °C/24 h）和退火处理（400 °C/1 h）以控制初始组织。退火处理后第二相仍存在，均匀化处理后第二相大部分溶解于基体中。研究了Al-7.9Zn-2.7Mg-2.0Cu合金均匀化及退火后的热变形行为，讨论了初始组织对合金热变形行为的影响。均匀化处理后的合金在低温变形时，溶质原子固溶到基体中，难以发生动态再结晶。在退火态合金中，保留的颗粒作为形核点，可以在较低的变形温度下通过颗粒激发形核（PSN）促进再结晶。随着变形温度的升高，PSN效应减弱，连续动态再结晶（CDRX）是均匀化和退火态合金的主要变形机制。均匀化处理后的合金在高变形温度和高应变速率下进行CDRX更容易、更高效。
The homogenization (470 °C/24 h) and annealing treatment (400 °C/1 h) before hot deformation were applied in the Al-7.9Zn-2.7Mg-2.0Cu alloy to control the initial microstructure. The secondary phase were remained after annealing treatment and most of secondary phases dissolved into the matrix after the homogenization. The hot deformation behaviors of homogenized and annealed Al-7.9Zn-2.7Mg-2.0Cu alloys were investigated, and effects of initial microstructure were discussed. The solute atoms dissolved into the matrix, and dynamic recrystallization was difficult at low deformation temperature in the homogenized alloy. In the case of the annealed alloy, the particles were remained to serve as nucleation sites, which can promote recrystallization by particle stimulated nucleation (PSN) at low deformation temperature. With increasing the deformation temperature, PSN effect was weak, and continuous dynamic recrystallization (CDRX) was the dominant deformation mechanism in the homogenized and annealed alloys. CDRX was easier and high-efficiency at high deformation temperature and high strain rate in the homogenized alloy.