Temperature-Time Superposition Effect on Compressive Properties of AZ31B Magnesium Composite Foams
Temperature-Time Superposition Effect on Compressive Properties of AZ31B Magnesium Composite Foams
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DOI：
10.3390/met8060434
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发表时间：
2018-06
期刊：
影响因子：
2.9
通讯作者：
Xing-chuan Xia;J. Wang;Yuanyi Peng;Nannan Wang;Xin He;Chuanrong Qiu;Jian Ding;Xueguang Chen
中科院分区：
文献类型：
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作者：
Xing-chuan Xia;J. Wang;Yuanyi Peng;Nannan Wang;Xin He;Chuanrong Qiu;Jian Ding;Xueguang Chen
采用改进的熔体发泡法制备了空心陶瓷微珠含量为10%（体积分数）的镁基复合泡沫。具有均匀孔结构的样品经受不同的加热温度（分别为150、250、320、400和500 ° C）和持续时间（分别为1、2、4、6和24 h）。采用X射线衍射（XRD）、差示扫描量热仪（DSC）、扫描电镜（SEM）和准静态单轴压缩试验研究了试样在热处理前后的微观结构和力学性能的变化。结果表明，随着加热温度的升高和保温时间的延长，β-Mg17Al12相逐渐溶解，产生固溶强化效应。同时，基体内应力松弛导致试样屈服强度和显微硬度下降。与未加热的泡沫相比，由于β-Mg17Al12相的溶解和内应力的释放，热处理后的泡沫具有较低的显微硬度、屈服强度和能量吸收能力。然而，几乎所有的处理后的复合泡沫材料的应变硬化指数较高，并讨论了原因。建议在实际应用中使用加热复合泡沫时应考虑更多因素。
Magnesium composite foams with 10 vol. % of hollow ceramic microspheres (CMs) were prepared by modified melt foaming method. Specimens with homogeneous pore structures were subjected to various heating temperature (150, 250, 320, 400, and 500 °C, respectively) and enduring times (1, 2, 4, 6, and 24 h, respectively). Evolution of microstructure and mechanical properties of the samples, before and after the heating processes were examined by applying X-ray diffraction technique (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and quasi-static uniaxial compression test. The results showed that as heating temperature and enduring time increasing, β-Mg17Al12 phases gradually dissolved, resulting in a solid-solution strengthening effect. Meanwhile, internal stress relaxation in the matrix leads to the decrease of yield strength and micro hardness of the specimens. When compared with the unheated foams, the treated specimens possessed lower micro-hardness, yield strength, and energy absorption capacity due to the dissolution of β-Mg17Al12 phases and the release of internal stress. However, higher strain hardening exponents for almost all of the treated composite foams were observed and the reasons were discussed. It is proposed that more factors should be taken into account when using heated composite foams in practical applications.