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采用真空辅助压力浸渗法短切碳纤维增强镁基复合材料(Csf/AZ91D),在变形温度为400~490℃、应变速率为0.001~0.1s-1、最大变形量为50%的条件下,研究了Csf/AZ91D复合材料的高温压缩塑性变形行为,观察了复合材料变形前后的微观组织,通过与基体镁合金对比探讨了镁基复合材料高温塑性变形机理。结果表明,复合材料在高温压缩过程中碳纤维发生了显著的偏转和折断,致使复合材料的应变软化现象较镁合金更为明显;短碳纤维细化了基体组织并增加了界面数量,使得复合材料表现出较高的应变速率敏感性;短碳纤维和晶界对基体强化作用随变形温度升高而减弱,而复合材料应力水平随变形温度增加而显著降低,表现出比镁合金更高的表观变形激活能。
Under the condition of deformation temperature of 400 ~ 490 ℃, strain rate of 0.001 ~ 0.1s-1 and maximum deformation of 50%, the vacuum assisted pressure impregnation method was used to cut carbon fiber reinforced magnesium matrix composites (Csf / AZ91D) The compressive plastic deformation behaviors of Csf / AZ91D composites at high temperature were investigated. The microstructures of the composites before and after deformation were observed. The plastic deformation mechanism of the composites at high temperature was discussed by comparison with the matrix magnesium alloy. The results show that the carbon fiber is obviously deflected and broken during high temperature compression, which makes the strain softening phenomenon of the composite more obvious than that of the magnesium alloy. The short carbon fiber refine the matrix structure and increase the number of interface, making the composite material performance The higher the strain rate sensitivity; the strengthening effect of short carbon fibers and grain boundaries on the matrix decreases with the increase of the deformation temperature, while the stress level of the composite decreases significantly with the increase of the deformation temperature, showing higher apparent deformation than the magnesium alloy Activate energy.