Compressive behavior of Mg alloy foams at elevated temperature
Compressive behavior of Mg alloy foams at elevated temperature
复制标题
泡沫镁合金高温压缩行为
DOI：
10.1016/j.jallcom.2019.04.323
复制
发表时间：
2019-08-15
影响因子：
6.2
通讯作者：
Xu, Jianrong
中科院分区：
文献类型：
--
作者：
Lu, Xiaotong;Zhang, Zhigang;Xu, Jianrong
研究了熔融法制备的闭孔泡沫镁合金的高温压缩行为。首先，采用扫描电子显微镜（SEM）、X射线能谱仪（EDS）和X射线衍射仪（XRD）对泡沫镁合金的微观结构、成分和物相进行了表征。然后，在室温（25 ℃）、200 ℃、400 ℃和500 ℃下对闭孔镁合金泡沫进行压缩试验。研究发现，温度对泡沫镁合金压缩行为的影响在高温和低温下是不同的。泡沫镁合金在室温下表现出脆性压缩行为，主要是由于泡孔壁的断裂。但在200 ℃ ~ 400 ℃温度范围内，纯脆性断裂模式转变为脆性断裂模式和韧性断裂模式的组合。这表明高温对泡沫基体的软化作用和低温时泡孔壁的塑性。结果表明，随着温度的升高，闭孔泡沫镁合金的压缩强度和能量吸收能力均降低。此外，基于能量吸收效率的观点，提出了一种新的定义致密化应变的方法。(C)2019爱思唯尔B. V.保留所有权利。
It is the purpose of this work to investigate compressive behavior of closed-cell Mg alloy foams fabricated by melting method at elevated temperature. First, the Mg alloy foams were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) for microstructure, composition and phases, respectively. Then, the compressive tests were carried out on closed-cell Mg alloy foams at room temperature (25 degrees C), 200 degrees C, 400 degrees C and 500 degrees C. It is found that the effect of temperature on compressive behavior of the Mg alloy foams is different between high temperature and low temperature. The Mg alloy foams exhibit a brittle compressive behavior at room temperature by the fracture of cell walls. However, the pure brittle fracture mode transforms into a combination of brittle fracture mode and ductile fracture mode at temperature in the range of 200 degrees C-400 degrees C. This indicates a soften effect of high temperature on the foams matrix and the plasticity of the cell walls at low temperature. It is concluded that the compressive strength and energy absorption capacity of the closed-cell Mg alloy foams decrease with the increasing temperature. Furthermore, a new method of defining the densification strain is proposed based on the perspective of energy absorption efficiency. (C) 2019 Elsevier B.V. All rights reserved.