Abstract

Based on a functionally graded material (FGM) design concept, the laminated-graded Ag-multilayer graphene/TC4 alloy self-lubricating composites (GTMAC) were prepared to overcome the poor friction and wear behaviors of TC4 alloy and expand engineering applications where friction is involved. Tribological experiments on GTMAC were carried out under different temperatures and loads in contrast with TC4 alloy (TC4) and homogeneous Ag-multilayer graphene/TC4 alloy self-lubricating composites (TMAC). The results show that GTMAC presents better friction and wear behaviors compared with TC4 and TMAC over a broad range of temperatures and loads. This is because of the synergistic effect of Ag and multilayer graphene, which are crushed and spread out in the sliding process, resulting in the formation of a lubricating film on the worn surface. Additionally, the equivalent stress distributions on the friction surfaces of TMAC and GTMAC are investigated using a finite-element method. The simulation results indicate that the GTMAC sample model with a smaller equivalent stress can avoid the occurrence of cracks and peeling of the surface material, so the the lubricating film is formed easily and remains for a longer working time.

摘要

基于功能梯度材料（FGM）的设计理念，制备了叠层梯度Ag-多层石墨烯/TC4合金自润滑复合材料（GTMAC），以克服TC4合金较差的摩擦磨损行为，扩大摩擦的工程应用。涉及。与TC4合金（TC4）和均质Ag-多层石墨烯/TC4合金自润滑复合材料（TMAC）相比，GTMAC在不同温度和载荷下进行了摩擦学实验。结果表明，与 TC4 和 TMAC 相比，GTMAC 在广泛的温度和负载范围内表现出更好的摩擦和磨损行为。这是因为Ag和多层石墨烯的协同作用，在滑动过程中被压碎和扩散，导致磨损表面形成润滑膜。此外，使用有限元方法研究了 TMAC 和 GTMAC 摩擦表面上的等效应力分布。仿真结果表明，具有较小等效应力的GTMAC样品模型可以避免表面材料的裂纹和剥离的发生，因此润滑膜容易形成并保持更长的工作时间。