Microstructure and cyclic deformation behaviour of the magnesium die-cast alloy AZ91D hp
Microstructure and cyclic deformation behaviour of the magnesium die-cast alloy AZ91D hp
复制标题
镁压铸合金AZ91D hp的显微组织和循环变形行为
DOI：
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
D. Eifler
中科院分区：
文献类型：
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作者：
Barbara Ebel;F. Walther;D. Eifler
摘要本文对压铸镁合金AZ91D hp进行了应力控制加载和恒幅加载试验。在载荷增加试验中测得的塑性应变幅度和温度变化允许用一个单一试样估计疲劳极限。在恒幅载荷下，应力幅值高于疲劳极限导致明显的循环硬化后，初始循环软化。与单调加载相比，观察到循环硬化。塑性变形主要发生在α相。相比之下，β相以非常脆的方式失效。光学和扫描电子显微镜研究表明，不同的裂纹扩展行为的α和β相。
Abstract In this investigation, stress-controlled load increase and constant amplitude tests have been carried out on the magnesium die-cast alloy AZ91D hp. The plastic strain amplitude and the temperature change measured in load increase tests allowed an estimation of the endurance limit with one single specimen. Under constant amplitude loading, stress amplitudes above the endurance limit lead to pronounced cyclic hardening after initial cyclic softening. Compared to monotonic loading, cyclic hardening was observed. The plastic deformation predominantly occurs in the α-phase. In contrast, the β-phase fails in a very brittle manner. Light and scanning electron microscopic investigations show the different crack propagation behaviour of the α- and β-phases.