Fabrication and strengthening mechanisms of magnesium matrix composites with bimodal microstructure induced by graphene nanoplatelets
Fabrication and strengthening mechanisms of magnesium matrix composites with bimodal microstructure induced by graphene nanoplatelets
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DOI：
10.1557/s43578-021-00112-w
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发表时间：
2021-02
影响因子：
2.7
通讯作者：
H. Shi;S. Xiang;Xiaoshi Hu;Xiaojun Wang;Chao Xu;K. Wu
中科院分区：
文献类型：
--
作者：
H. Shi;S. Xiang;Xiaoshi Hu;Xiaojun Wang;Chao Xu;K. Wu
镁基复合材料在航空航天、汽车、移动的电子和生物医学应用中具有提高能量效率和系统性能的潜力。本文制备了一种新型的具有双峰结构的石墨烯纳米片（GNP）增强镁基复合材料。将气泡辅助组装法、液态冶金法和热挤压法相结合，粉碎了Mg/GNP纳米片的团聚，构建了Mg/GNP复合材料的双峰结构。对增强机理的理论计算表明，复合材料强度的提高主要是由纳米颗粒的晶粒细化效应和载荷传递效应所贡献的。由于晶粒尺寸与相应增加的屈服强度之间存在凹函数关系，双态组织显著提高了复合材料的强化效率，其强化效果上级优于晶粒均匀细化的复合材料。这种行为展示了复合材料结构设计的科学和技术优势的新可能性。
Magnesium (Mg) matrix composites have the potential to improve energy efficiency and system performance in aerospace, automobile, mobile electronics and biomedical applications. In this work, a novel graphene nanoplatelets (GNPs) reinforced Mg matrix composites with the bimodal microstructure have been fabricated. The combination of bubbles assisted assembly method, liquid metallurgy process and hot extrusion was developed to smash the agglomeration of nanoplatelets and construct the bimodal microstructure of the Mg/GNPs composites. The theoretical calculation for strengthening mechanisms showed that the enhanced strength of the composites were mainly contributed by the grain refinement effect and the load transfer effect by GNPs. Because of the concave function relationship between the grain size and the corresponding increased yield strength, the bimodal microstructure significantly improved the strengthening efficiency of the composites, which was superior to the composites with uniform refined grains. This behavior demonstrated new possibilities for scientific and technological advantages with architecture design of composites.