Acta Metallurgica Sinica (English Letters) ›› 2024, Vol. 37 ›› Issue (3): 467-483.DOI: 10.1007/s40195-023-01560-5

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Interface Design Strategy for GNS/AZ91 Composites with Semi-Coherent Structure

Jing-Peng Xiong1, Yi-Qi Zeng1,2, Jin-Long Liu1, Wei-Cheng Wang1, Lan Luo1,2, Yong Liu1()   

  1. 1Key Laboratory of Lightweight and High Strength Structural Materials of Jiangxi Province, School of Advanced Manufacturing, Nanchang University, Nanchang 330031, China
    2School of Physics and Materials Science, Nanchang University, Nanchang 330031, China
  • Received:2022-11-30 Revised:2023-02-20 Accepted:2023-03-04 Online:2024-03-10 Published:2023-05-10
  • Contact: Yong Liu, liuyong@ncu.edu.cn

Abstract:

The interfacial structure plays an important role in the mechanical properties of magnesium matrix composite (MMCs) reinforced with graphene nanosheet (GNS) due to their poor wettability with the Mg matrix. An interface design strategy was proposed to form the semi-coherent interfacial structure with superior bonding strength. The lattice mismatch and interfacial bonding strength between Mg/rare earth oxide/carbon were utilized as key characteristics to evaluate the interfacial structure. Lanthanum oxide (La2O3) was selected as the intermediate candidate due to its low lattice mismatch and high interfacial bonding strength. To identify the interfacial structure of Mg/La2O3/graphene, first-principles calculations were conducted to calculate the ideal work of separation and electronic structure of the interfaces. Results demonstrated the presence of strong ionic and covalent interactions at the interface, which theoretically verified the strong interfacial bonding strength among Mg/La2O3/graphene interfaces. To experimentally validate the interface strength, MMCs with the interface structure of Mg/La2O3/GNS were developed. The formation of in-situ La2O3 led to the successful attainment of semi-coherent structures between Mg/La2O3 and La2O3/GNS, resulting in high strength and good ductility of the composite. Overall, this work proposes a new approach to interface design in MMCs with an enhancement of mechanical properties.

Key words: Interface design strategy, Magnesium matrix composite, Graphene nanosheets, Semi-coherent interface, Mechanical properties