Abstract The open-cell Mg-xSi (x = 1, 5, 9 wt%) foams reinforced by in-situ Mg2Si compounds were prepared by pressure infiltration process. The optical microscopy (OM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) were used to investigate the microstructure, chemical components and phase compositions of the foams, respectively. Compressive strength and energy absorbing characteristics of the foams containing varied Si additions were assessed via compressive test. The experimental results exhibit that the microstructure of the foams is depending on Si content. Mg 1Si foams are mainly composed of eutectic Mg2Si and α-Mg, while Mg 5Si and Mg 9Si foams mainly consist of the primary Mg2Si, eutectic Mg2Si and α-Mg. The compressive strength of the foams is elevated initially and then decreased when the Si content is increased from 1 to 9 wt%, but the energy absorption capacity is reduced with the increase of Si content. The related mechanism was discussed and a schematic diagram was drawn to reflect the role of coarse primary Mg2Si in fracture behavior of the foams.

中文翻译：

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Si含量对原位Mg2Si化合物增强开孔Mg复合泡沫微观结构和压缩性能的影响

摘要 采用压力渗透法制备了原位Mg2Si化合物增强的开孔Mg-xSi (x = 1, 5, 9 wt%)泡沫。分别采用光学显微镜(OM)、扫描电子显微镜(SEM)、能量色散X射线光谱(EDS)和X射线衍射(XRD)研究泡沫的微观结构、化学成分和相组成。通过压缩试验评估了含有不同硅添加物的泡沫的压缩强度和能量吸收特性。实验结果表明，泡沫的微观结构取决于硅含量。Mg 1Si泡沫主要由共晶Mg2Si和α-Mg组成，而Mg 5Si和Mg 9Si泡沫主要由初生Mg2Si、共晶Mg2Si和α-Mg组成。当Si含量从1wt%增加到9wt%时，泡沫的抗压强度先升高后降低，但吸能能力随着Si含量的增加而降低。讨论了相关机理并绘制了示意图以反映粗初生Mg2Si在泡沫破裂行为中的作用。