Hot deformation mechanisms and microstructure evolution of SiCp/2014Al composite
Hot deformation mechanisms and microstructure evolution of SiCp/2014Al composite
复制标题
SiCp/2014Al复合材料的热变形机制及显微组织演化
DOI：
10.1016/j.jallcom.2017.06.065
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发表时间：
2017-10-25
影响因子：
6.2
通讯作者：
Ma, Zongyi
中科院分区：
文献类型：
--
作者：
Huang, Zhiye;Zhang, Xingxing;Ma, Zongyi
研究了搅拌铸造和热挤压14vol%SiCp/2014 Al复合材料在温度为355 ~ 495 ℃、应变速率为0.001 ~ 1 s（-1）条件下的热变形行为，包括微观组织演变和损伤形成。基于改进的动态材料模型（MDMM），优化应力应变率拟合，构建精确的加工图。此外，绘制了应变速率敏感性图，表明温度对变形机制的影响比应变速率更显著。耗散效率随温度的变化曲线表明：（1）在400 ℃时，合金从动态回复（DRV）向动态再结晶（DRX）转变，（2）在400-440 ℃时，合金发生动态晶粒长大（DGG）;（iii）存在450 ℃的等凝聚点（T-eq）（类似于0.8 T-m），高于该值，晶界弱化并有助于塑性变形。在440 ℃时温度灵敏度的特殊波动是由异常晶粒生长引起的。(C)2017爱思唯尔B. V.保留所有权利。
Hot deformation behavior of a stir cast and hot extruded 14 vol% SiCp/2014Al composite was studied at temperatures from 355 to 495 degrees C and strain rates from 0.001 to 1 s(-1), including microstructure evolution and damage formation. Stress-strain rate fitting was optimized to construct accurate processing maps based on modified dynamic materials model (MDMM). In addition, the strain rate sensitivity maps were plotted, indicating more significant effect of temperature on deformation mechanism than strain rate. The dissipation efficiency versus temperature curves indicated: (i) a transition from dynamic recovery (DRV) to dynamic recrystallization (DRX) at 400 degrees C; (ii) occurrence of dynamic grain growth (DGG) at 400-440 degrees C; (iii) existence of equicohesive point (T-eq) of 450 degrees C (similar to 0.8 T-m) above which grain boundaries weakened and contributed to plastic deformation. The particular fluctuation of temperature sensitivity at 440 degrees C was caused by an abnormal grain growth. (C) 2017 Elsevier B.V. All rights reserved.