不同环境下AlSiFeMm非晶纳米晶涂层摩擦磨损行为研究

Wear Behaviors of As-sprayed AlSiFeMm Amorphous/Nanocrystalline Coating in Different Environments

目的研究AlSiFeMm(Mm为镍包混合稀土)非晶纳米晶涂层在干摩擦和3.5%NaCl溶液中的摩擦磨损行为。方法采用Rtec(MFT-3000)往复式磨损试验机测试涂层在干摩擦条件和有腐蚀介质条件下的摩擦磨损性能,使用LEXTOL3000-IR非接触三维表面轮廓仪测定涂层的磨损体积和磨痕的三维形貌,利用扫描电子显微镜对磨痕进行形貌观察和成分分析。结果铝基非晶纳米晶涂层的摩擦系数随着载荷的增加而不断减小。干摩擦条件下,铝基非晶纳米晶涂层的磨损率随着载荷的增加而增大,当磨损速度为10 mm/s、载荷为15 N时,涂层相对耐磨性为6061铝合金的2.5倍,其磨损机制为脆性剥落、磨粒磨损,并伴随氧化磨损。在3.5%NaCl溶液中,涂层的磨损率随着载荷的增加而逐渐降低,当磨损速度为35 mm/s、载荷为30N时,涂层的耐磨性能约为6061铝合金的8倍,其失效机制主要为剥层磨损和腐蚀磨损。结论铝基非晶纳米晶复合涂层在干摩擦和腐蚀介质中均表现出较为优异的耐磨性能,可以作为轻质合金涂层应用于表面防护领域。

The work aims to investigate the sliding wear behaviors of the AlSiFeMm(Mm is Ni-wrapped rare earth elements) amorphous/nanocrystalline coating under dry friction and 3.5%NaCl solution conditions. Rtec(MFT-3000) reciprocating ball-on-block tester was used to measure tribological properties of the coating under dry friction and corrosive medium. The wear volumes and 3-dimensional profiles of worn tracks of the coating were measured by LEXT OL 3000-IR non-contact three-dimensional surface profilometer. The worn surface morphology and components were analyzed by scanning electron microscopy(SEM). The friction coefficient of Al-based amorphous/nanocrystalline coating decreased with the increase of load.Under dry friction conditions, the wear rate of coating increased with the increase of load. The wear resistance of the coating was about 2.5 times that of the 6061-Al alloy with sliding speed of 10 mm/s and load of 15 N. The wear mechanism was brittle flaking, abrasive wear and oxidative wear. In 3.5%NaCl solution, the wear rate of the coating gradually decreased with the increase of load. When the sliding speed was 35 mm/s and load was 30 N, the wear resistance of the coating in corrosive medium was about 8 times that of 6061-Al alloy. The wear mechanism of the coating was delamination and corrosion damage. The Al-based amorphous/nanocrystalline coating has excellent wear resistance in dry friction and corrosive media, and can be used as a lightweight alloy coating in the field of surface protection.