纳米SiO2颗粒增强镍基复合镀层的组织与微动磨损性能研究

采用电刷镀技术在45#钢表面制备了纳米SiO2颗粒增强镍基复合镀层,用扫描电子显微镜和透射电子显微镜观察分析了复合镀层的表面形貌和微观组织形貌,用纳米压痕仪测试了复合镀层的微观力学性能,并采用PLINT型高温微动疲劳试验机考察了复合镀层在室温至500 ℃下的微动磨损行为.结果表明:纳米SiO2颗粒促进了镀层的晶粒细化,提高了镀层的力学性能,复合镀层的硬度和弹性模量分别比镍镀层提高了2.01GPa和5 GPa,从而改善了镀层的微动磨损性能;复合镀层的耐磨性能约为镍镀层的2倍,这是由于纳米SiO2颗粒对复合镀层具有超细晶强化、硬质点弥散强化以及高密度位错强化机制所致.

Microstructure and Fretting Wear Behavior of Ni based Composite Coatings Reinforced by SiO2 Nanoparticles

Ni based composite coatings reinforced by SiO_2 nanoparticles were prepared on AISI-1045 steel by electro-brush plating. Surface morphologies and microstructures were observed by scanning electron microscope and transmission electron microscope, their micro mechanical properties were examined by nano indentation, and fretting wear behavior from room temperature to 500 was investigated on a PLINT fretting wear test rig. It was found that incorporation of SiO_2 nanoparticles refined microstructure and increased mechanical properties, which led to improvement of anti-fretting wear of composite coatings. Anti-fretting wear of composite coatings was improved by 2 times, which was attributed to thinner crystals strengthening, dispersion strengthening and high-density dislocations strengthening of SiO_2 nanoparticles in the composite coatings.