AZ80合金高温变形行为及加工图

为实现AZ80合金塑性成形的数值模拟和制定其合理的热加工工艺,利用热模拟机对AZ80合金进行不同变形温度和应变速率的高温压缩变形行为研究.结果表明:AZ80合金的高温流动应力-应变曲线主要以动态回复和动态再结晶软化机制为特征,峰值应力随变形温度的降低或应变速率的升高而增加;在真应力-应变曲线基础上,建立的AZ80合金高温变形的本构模型较好地表征其高温流变特性,模型计算精度高;同时,利用建立的AZ80合金的DMM加工图分析其变形机制和失稳机制,从提高零件力学性能角度考虑,可以优先选择变形温度为300～350 ℃、应变速率为0.001～0.01 s-1的工艺参数.

Study on High-Temperature Deformation Behavior and Processing Map of AZ80 Alloy

In order to realize numerical simulation of plastic forming and to establish the reasonable hot formation process, the high-temperature compressive deformation behavior of AZ80 alloy was studied at various deformation temperatures and strain rates with Gleeble-1500. The experimental results show that the softening mechanism of dynamic recovery and dynamic recrystallization is a feature of high-temperature flow stress-strain curves of AZ80 alloy, and the peak stress increases with decreasing of the deformation temperature or increasing of the strain rate. Based on the true stress-strain curves, the established constitutive equation represents high temperature flow behavior of AZ80 alloy, and the calculated results of the flow stress are in good agreement with the experimental results of high temperature deformation of AZ80 alloy. Meanwhile, the obtained processing map of Dynamic Material Modeling (DMM) is used to analyze the deformation mechanism and the destabilization mechanism of AZ80 alloy; the optimal deformation processing parameters are the deformation temperatures ranging from 300 to 350 oC and strain rates ranging from 0.001 to 0.01 s-1, when the mechanical property of AZ80 alloy is taken into consideration.