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对SiC颗粒增强6061铝基复合材料在一定的应变速率(0.0001~0.1 s-1)和一定的变形温度(300~450℃)下进行热压缩试验,对热变形行为进行分析。结果表明:复合材料流变应力随着应变速率的增大而增大,随着变形温度的升高而降低,呈现出正应变速率敏感性。复合材料的热流变行为可以用双曲正弦形式的本构方程来描述,并通过线性回归分析,计算出复合材料的应变敏感指数n为8.0678,变形激活能Q为366.27 kJ/mol,其变形机制为晶格扩散控制的弥散强化机制。同时,观察了复合材料微观变形组织,可以看出热压缩后晶粒明显被拉长,颗粒在变形过程中重新排布,但是在高温低应变速率下,因动态再结晶的发生,这种现象不是很明显。
The hot deformation behavior of SiC particle reinforced 6061 aluminum matrix composite under certain strain rate (0.0001 ~ 0.1 s-1) and some deformation temperature (300 ~ 450 ℃) was investigated. The results show that the flow stress of composites increases with the increase of strain rate, decreases with the increase of deformation temperature, and shows the positive strain rate sensitivity. The thermo-rheological behavior of the composites can be described by the constitutive equation of the hyperbolic sine form, and by means of the linear regression analysis, the strain-sensitive index n of the composite is calculated to be 8.0678 and the deformation activation energy Q is 366.27 kJ / mol. The deformation mechanism Dispersion enhancement mechanism for lattice diffusion control. At the same time, the microstructure of the composite was observed. It can be seen that the grains were obviously elongated after hot compression and the particles were rearranged during the deformation. However, under the condition of high temperature and low strain rate, the dynamic recrystallization occurred. not so obvious.