Influence of elevated temperatures on the cyclic deformation behaviour of the magnesium die-cast alloys AZ91D and MRI 230D
Influence of elevated temperatures on the cyclic deformation behaviour of the magnesium die-cast alloys AZ91D and MRI 230D
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DOI：
10.1016/j.msea.2007.10.003
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发表时间：
2008-06-15
期刊：
影响因子：
6.4
通讯作者：
Eifler, Dietmar
中科院分区：
文献类型：
--
作者：
Ebel-Wolf, Barbara;Walther, Frank;Eifler, Dietmar
采用压铸法对镁合金AZ 91 D和MRI 230 D进行了研究。细晶组织由枝晶状镁固溶体和枝晶间析出物组成。在应力控制载荷增加试验和恒定振幅试验中，通过在室温和T= 150 ℃下测量机械应力-应变滞后来表征循环变形行为。MRI合金导致更高的塑性应变幅度，但在两种温度下的寿命更长。载荷增加试验允许在室温和高温下对疲劳极限进行可靠的短时间估计。基于物理的疲劳寿命计算方法“PHYBAL”可以根据一次载荷增加试验和两次恒幅试验中确定的循环变形数据计算镁合金的寿命，与常规确定的S-N曲线非常一致。(c)2007 Elsevier B. V.保留所有权利。
The magnesium alloys AZ91D and MRI 230D were investigated in form of die-cast specimens with a cast skin. The fine-grained microstructure consists of a dendritic magnesium solid solution and interdentritic precipitates. The cyclic deformation behaviour was characterised in stress-controlled load increase tests and constant amplitude tests by means of mechanical stress-strain hysteresis measurements at room temperature and at T= 150 degrees C. The MRI alloy leads to higher plastic strain amplitudes and nevertheless higher lifetimes for both temperatures. Load increase tests allow a reliable short-time estimation of the endurance limit under both, room and elevated temperatures. With the physically based fatigue life calculation method "PHYBAL" the lifetime of the magnesium alloys can be calculated on the basis of cyclic deformation data determined in one load increase test and two constant amplitude tests in excellent agreement with the conventionally determined S-N curve. (c) 2007 Elsevier B.V. All rights reserved.