Hot deformation behavior of Al18B4O33w/ZK60 magnesium matrix composite
Hot deformation behavior of Al18B4O33w/ZK60 magnesium matrix composite
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DOI：
10.1016/j.msea.2008.03.010
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发表时间：
2008-07
期刊：
影响因子：
6.4
通讯作者：
C. Y. Wang;Kai Wu;M. Zheng
中科院分区：
文献类型：
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作者：
C. Y. Wang;Kai Wu;M. Zheng
研究了体积分数为20%的ZK 60镁合金的热变形行为，在523- 723 K温度范围和0.001- 10 s-1应变速率范围内对Al 18 B4 O 33晶须进行了压缩实验。在一定的应变条件下，变形行为主要取决于应变速率和温度。分析了流变行为随变形温度和应变速率的变化规律。在不同温度和应变速率下，热压缩过程中的显微组织演化主要表现为孪晶、位错滑移和动态再结晶。用透射电子显微镜（TEM）观察它们。结果表明，孪晶发生在较低温度和变形早期。孪晶是低温下高应变硬化率的主要原因。该材料在较高温度和中等应变速率下表现出动态再结晶，这是在较高温度下发生流动软化的原因。Al_（18）B_4 O_（33）晶须促进动态再结晶形核。在热变形过程中形成细小的位错亚结构，导致亚晶的形成。
The hot deformation behavior of ZK60 magnesium alloy reinforced with 20vol.% of Al18B4O33whisker was investigated by compression testing in temperature range of 523–723K and strain rate range of 0.001–10s−1. The deformation behavior was mainly dependent on strain rate and temperature on certain strain condition. Variations of flow behavior with deformation temperature as well as strain rate were analyzed. The microstructural evolution at different temperatures and strain rates are mainly characterized by twinning, dislocation slip and dynamic recrystallization (DRX) during the hot compression. They were observed by transmission electronic microscope (TEM). It is shown that twinning occurred at lower temperature and earlier deformation stage. Twinning is the main reason for the high strain hardening rate at relatively low temperature. The material showed DRX at higher temperature and moderate strain rate, which is the reason for flow softening at relatively high temperature. Al18B4O33whiskers promote nucleation of DRX. A fine dislocation substructure forms upon hot deformation, leading to subgrain formation.