超音速火焰喷涂Fe基非晶合金涂层材料的摩擦磨损性能研究

Friction and Wear Properties of HVAF Sprayed Fe-based Amorphous Alloy Coatings

目的通过优化涂层制备工艺,制备致密的Fe基非晶合金涂层,以提高非晶合金涂层的耐磨性。方法采用活性燃烧高速燃气超音速火焰喷涂(AC-HVAF)技术,通过工艺优化,制备了组织致密的Fe基非晶合金涂层。利用场发射扫描电子显微镜、X射线衍射仪、维氏显微硬度计、摩擦磨损试验机、三维光学轮廓仪等设备,对非晶合金涂层的组织结构、摩擦性能和磨损机制进行了深入分析。结果 Fe基非晶合金涂层呈现典型的非晶结构,涂层厚度在300μm左右,涂层的平均显微硬度值高达1000HV0.1。在干摩擦试验条件下,Fe基非晶合金涂层的磨损量远低于304不锈钢材料,磨损率是304不锈钢基体的1/3~1/2。Fe基非晶合金涂层的磨损机制以疲劳磨损为主,伴随着氧化磨损。氧化磨损主要是由干摩擦过程中产生的摩擦热导致,氧化磨损加速了片层剥落。结论 Fe基非晶合金涂层孔隙率的降低和非晶相含量的提高,有利于稳定摩擦系数和改善涂层的耐磨损性能。

The work aims to improve wear resistance by optimizing coating preparation process and preparing dense Fe-based amorphous alloy coatings. Dense Fe-based amorphous alloy coatings were fabricated by adopting activated combustion high velocity air fuel（AC-HAVF） technology and optimizing process. Microstructure, tribological properties and wear mechanisms of the as-sprayed coatings were thoroughly analyzed with scanning electron microscope（SEM）, X-ray diffractometer（XRD）, vickers microhardness tester, friction and wear tester, 3 D optical profiler, etc. The microstructure of Fe-based amorphous alloy coatings presented amorphous structure. The thickness of as-sprayed coatings was nearly 300 μm. Average microhardness of the coatings was up to 1000 HV0.1. Moreover, wear mass loss of the Fe-based amorphous alloy coatings was far lower thanthat of 304 stainless steel. Wear rate of the Fe-based amorphous alloy coatings was 1/3~1/2 of 304 stainless steel substrate. The wear mechanism of Fe-based amorphous alloy coatings was mainly fatigue wear, accompanied by oxidation wear. Oxidation wear was mainly caused by friction heat generated during dry sliding process, which accelerated delamination of the coatings. Lower porosity and higher amorphous content of Fe-based amorphous alloy coatings help to improve wear resistance and stabilize friction coefficient.