Hot deformation behavior and processing map of a new type Mg-6Zn-1 Gd-1Er alloy
Hot deformation behavior and processing map of a new type Mg-6Zn-1 Gd-1Er alloy
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新型Mg-6Zn-1Gd-1Er合金的热变形行为及加工图
DOI：
10.1016/j.jallcom.2021.158700
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发表时间：
2021-01-18
影响因子：
6.2
通讯作者：
Liu, Longfei
中科院分区：
文献类型：
--
作者：
Che, Bo;Lu, Liwei;Liu, Longfei
利用Gleeble-3500热模拟试验机研究了新型Mg-6 Zn-1Gd-1 Er合金在180 ℃ ~ 380 ℃温度范围内、应变速率为10（-3）s（-1）~ 10 s（-1）的热变形行为。真应力-应变曲线表明，流变应力随应变速率的增加和温度的降低而增加。采用基于双曲正弦方程的本构方程对该合金中高温和低温两个变形区间的流变应力进行了数值模拟。根据0.2、0.4、0.6和0.8真应变的实验数据，建立了加工图，确定了最佳加工参数为330 ℃ ~ 380 ℃和0.001 s（-1）~ 0.1 s（-1）。基于加工图峰值功率耗散效率对应的应变速率进行微观组织分析，发现低温变形过程中孪晶是主要的变形机制。随着温度的升高，合金形成了典型的项链状连续动态再结晶组织。当温度达到380 ℃时，稳定区的电子背散射衍射（EBSD）结果表明，以典型的不连续动态再结晶（DDRX）和CDRX为主要变形机制，形成了较强的< 0001 >//CD织构，并伴有较弱的次级织构成分。在失稳区，变形机制主要为CDRX和孪晶，在380 ° c/10 s（-1）时形成明显的双峰织构。(C)2021爱思唯尔有限公司版权所有。
The hot deformation behavior of a new type Mg-6Zn-1Gd-1Er alloy was investigated in the temperature range of 180 degrees c-380 degrees c and strain rate of 10(-3) s(-1) -10 s(-1) with the Gleeble-3500 thermal simulation testing machine. The true stress-strain curves showed that flow stress increased with the increasing of strain rate and decreasing of temperature. The constitutive equations based on hyperbolic sine equation were used to demonstrate the flow stress of two intervals of medium-high and low temperature deformation for this alloy. Processing maps were developed based on the experimental data of true strains of 0.2, 0.4, 0.6 and 0.8, which the optimal processing parameters were determined as 330 degrees c-380 degrees c and 0.001 s(-1) -0.1 s(-1). Microstructure analysis based on the strain rate corresponding to peak efficiency of power dissipation of processing map found that twinning was the dominate deformation mechanisms during low temperature deformation. With the increasing of temperature, a typical necklace-typed microstructure resulted by continuous dynamic recrystallization (CDRX) was formed. When the temperature was up to 380 degrees c, the electron backscatter diffraction (EBSD) results of stable region showed that a typical discontinuous dynamic recrystallization (DDRX) and CDRX were the main deformation mechanisms, and formation a strong < 0001 > //CD texture together with secondary weaker texture component. At the instability region, it can be found that CDRX and twinning were the main deformation mechanisms, and an obvious bimodal texture formed at 380 degrees c/10 s(-1). (C) 2021 Elsevier B.V. All rights reserved.