Compressive plastic deformation of an AS21X magnesium alloy produced by high pressure die casting at elevated temperatures
Compressive plastic deformation of an AS21X magnesium alloy produced by high pressure die casting at elevated temperatures
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DOI：
10.1016/j.msea.2003.09.101
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发表时间：
2004-02-25
期刊：
影响因子：
6.4
通讯作者：
Cerri, E
中科院分区：
文献类型：
--
作者：
Barbagallo, S;Cavaliere, P;Cerri, E
本文研究了高压铸造Mg-Al-Si-RE（RE =稀土）合金在125-300 ℃、10（-5）~ 10（-1）s（-1）温度和应变速率范围内的热变形行为。在高压压铸状态下或在415 ℃（固溶温度）下暴露2小时后使样品变形，以评价对变形的任何不同响应。在低温和高应变速率下应变的样品中观察到相对于压缩轴成45度的过早断裂。应力-应变曲线表现出典型的趋势的材料，其中变形是恢复控制在高Z制度（Z是Zener-Hollomon参数），而在低应变速率和高T，流动曲线表现出软化典型的再结晶现象。为了更好地理解微观结构，本构参数进行了评估。光学显微镜分析已进行相关的微观结构的变形参数在所有的测试条件。微观结构的调查表明，在高Z和再结晶过程中的低应变率-高温制度的变形过程中的恢复机制的存在。(C)2003 Elsevier B. V.保留所有权利。
The hot deformation behaviour of an Mg-Al-Si-RE (RE = rare earth) alloy produced by high pressure die casting has been investigated by means of compression tests in the temperature and strain rate ranges of 125-300 degreesC and 10(-5)to10(-1)s(-1). The samples were deformed in the high pressure die casting state or after an exposure at 415 degreesC for 2 h (solution temperature) to evaluate any different response to deformation. A premature fracture at 45degrees with respect to the compression axis was observed in samples strained at low temperatures and high strain rates. The stress-strain curves exhibit the trend typical of materials in which deformation is recovery-controlled in the high Z regime (Z is the Zener-Hollomon parameter), while at low strain rates and high T, the flow curves exhibit a softening typical of recrystallisation phenomena. Constitutive parameters were evaluated in order to understand the microstructure better. Light microscopy analysis has been performed to correlate the microstructure to the deformation parameters in all the tested conditions. Microstructural investigations indicate the presence of recovery mechanisms at high Z and recrystallisation during deformation in the low strain rate-high temperature regime. (C) 2003 Elsevier B.V. All rights reserved.