石墨含量对石墨/TiC/镍基合金复合涂层微观组织与摩擦学性能的影响

摘要

In order to reduce the friction coefficients and further improve the anti-wear properties of Ni-base alloy coatings reinforced by TiC particles,graphite/TiC/Ni-base alloy (GTN) coatings were prepared on the surface of 45 carbon steel.The effects of graphite content on the microstructure and tribological properties of the GTN coatings were investigated.The results show that the addition of graphite to the GTN coatings may greatly reduce the friction coefficients and improve their wear resistance.The 6.56GTN and 12.71GTN coatings exhibit excellent integrated properties of anti-friction and wear resistance under low and high loads,respectively.Under a low load,the wear mechanisms of the GTN coatings are mainly multi-plastic deformation with slight abrasive wear and gradually change into mixture of multi-plastic deformation,delamination and micro-cutting wear with the increase of graphite fraction.As the load increases,the main wear mechanisms gradually change from micro-cracks,micro-cutting and adhesive wear to micro-cutting and micro-fracture with the increase of graphite fraction.%为了降低TiC/镍基合金复合涂层的摩擦因数并增强其耐磨性能,运用等离子喷涂技术在45#钢表面制备石墨/TiC/镍基合金(GTN)复合涂层.研究石墨含量对GTN涂层组织和摩擦学性能的影响.结果表明,石墨的加入有效地降低了涂层的摩擦因数,提高了其耐磨性.6.56GTN涂层和12.71GTN涂层分别在低载荷与高载荷摩擦条件下呈现出优异的减摩耐磨性能.在低载荷条件下,GTN涂层的磨损机理主要表现为多次塑变磨损,伴有轻微的磨粒磨损,且随着石墨含量的增加逐渐转变为多次塑变、层脱和微切削磨损；在载荷增加后,脆性断裂、微观切削和粘着为其主要的磨损机理,且随着石墨含量的增加逐渐转变为微观切削和脆性剥落.