热应力高能喷丸石墨烯/铝基复合材料微观结构演变及表层力学性能研究

Graphene nano-sheets reinforced aluminum matrix composite (GNs/Al) has a broad application prospect in high-end manufacturing such as aerospace and automobile industries due to its excellent mechanical property. However, some of the key components made of composite materials faced with fatigue and wear failures in service. This project proposes a thermal stress high energy shot peening to produce a gradient nanostructure on the surface of GNs/Al to improve its surface mechanical property. It is focused on the preparation of surface gradient nanostructure of metal matrix composite, nanostructure evolution and surface mechanical property. The purposes are to understand the role of graphene nano-sheets reinforcement in the formation of the surface gradient nanostructure by shot peening in aluminum matrix composite, to explore its controllable preparation, and to clarify the effect of graphene nano-sheets reinforcement on the evolution behavior of surface gradient nanostructure under external loading and high temperature, optimizing the stablity of its surface gradient nanostructure. The objective is to establish the intrinsic relationship between surface nanostructure formation, stablity and its surface mechanical property. The goal is to improve the surface mechanical property of graphene nano-sheets reinforced aluminum matrix composite by thermal stress high energy shot peening. This research provides useful guidance for the preparation of surface gradient nanostructure and optimizing the surface mechanical property of aluminum matrix composites.

石墨烯纳米片增强铝基复合材料(GNs/Al)具有优异的力学性能,在航空航天、汽车制造等高端制造领域有着广阔的应用前景。然而，由复合材料制备的一些关键零部件在服役过程中面临着疲劳及磨损失效问题。因此，本项目提出采用热应力高能喷丸强化工艺在GNs/Al表层制备梯度纳米结构优化其表层力学性能。深入开展复合材料表层梯度纳米结构的制备、微观结构演变以及表层力学性能研究，旨在理解石墨烯纳米片增强体在铝基复合材料喷丸强化制备表层梯度纳米结构中的作用，探索复合材料表层梯度纳米结构的可控制备；明晰石墨烯纳米片增强体对表层梯度纳米结构在外载荷及高温下演变的影响机制，优化复合材料表层梯度纳米结构稳定性；最终建立复合材料表层梯度纳米结构的形成、稳定性与表层力学性能的内在关联，实现热应力高能喷丸优化GNs/Al性能。本研究为实现复合材料表层梯度纳米结构的可控制备以及优化铝基复合材料性能提供指导。

石墨烯纳米片增强铝基复合材料(GNs/Al)具有优异的力学性能,在航空航天、汽车制造等高端制造领域有着广阔的应用前景。然而，由复合材料制备的一些关键零部件在服役过程中面临着疲劳及磨损失效问题。本项目首先通过粉末冶金方法制备了石墨烯纳米片增强铝基复合材料，研究了增强体含量、尺寸、金属离子掺杂等对其微观结构和力学性能的影响，阐述了增强体对复合材料力学性能影响的微观机理。在此基础上，对GNs/Al复合材料表面进行改进的高能喷丸强化处理优化其表面力学性能，探索了石墨烯增强体在GNs/Al复合材料表层梯度纳米结构制备中的作用。项目进一步研究了所制备的表层梯度纳米结构在等温退火条件下的热稳定性，明晰了增强体对表层梯度纳米结构热稳定性的作用及机理。最终建立了复合材料表层梯度纳米结构的形成、稳定性与表层力学性能的内在关联，优化了GNs/Al复合材料表层力学性能。项目研究结果对拓宽喷丸强化技术在我国机械制造业上的应用，提升复合材料零部件性能方面具有十分重要的意义。