【摘要】 通过建立镁合金等通道转角挤压过程的热力耦合有限元分析模型,对其变形过程中的温度场分布进行分析,并通过微观组织观察和XRD分析,获取变形温度对镁合金变形行为的影响规律。结果表明:等通道挤压过程中试件温度分布不均匀,在模具转角剪切部位温度显著升高,且存在明显的温度梯度。XRD分析和微观组织观察显示,AZ31镁合金变形后,锥面衍射强度显著增强,且镁合金的再结晶速度随着变形温度的升高而显著加快。结合变形过程中温度场的分布状况,建议AZ31镁合金等通道转角挤压的合理变形温度设定为250℃。更多还原

【Abstract】 A thermomechanical coupled finite element model was established and the temperature distribution of the magnesium work-piece during equal channel angular pressing(ECAP) was analysed.The effect of deformation temperature on deformation behavior of magnesium alloy was acquired by XRD analysis and microscopic examination.The results show that the distribution of temperature is not uniform during equal channel angular pressing,there exists obvious temperature gradient and the temperature increases significantly in the mold angle shear part.The XRD analysis and microscopic examination show that the pyramidal face diffraction intensity enhances significantly,the recrystallization rate of magnesium alloy increases obviously with the increase of deformation temperature.The optimal deformation temperature of 250 ℃ is obtained according to the temperature distribution.更多还原