Evaluation of tribological properties of nano-multilayered thin hard coatings by a slurry jet impact test and its application

为了快速评价单层或多层硬质涂层的摩擦学性能，我们提出了一种新型的固体颗粒冲击试验方法。(1)利用1μm氧化铝颗粒在垂直于TiN、CrN、TiCN薄膜的高速冲击下，涂层比基材具有更高的耐磨性，从而当涂层被渗透时，磨损率显著增加到基材的较高水平。(2)通过浆液射流冲击试验，发现涂层具有比基材更高的耐磨性。可以快速、高重复性地评价PVD涂层钻头的磨损性能。(3)沉积在钻头上的PVD涂层与作为参考样品的平板样品的耐磨性相同。(4)对于本文研究的涂层，TiN涂层的耐磨性最好，而CrN涂层的耐磨性最差。(5)CrNi涂层的耐磨性随着Ni含量的增加而降低。(6)CrN(CrNi)涂层的耐磨性等级与其微观硬度有很好的相关性。因此，在评价涂层和涂层工具时，它可以优先用作筛选试验。

We proposed slurry jet, a new type of solid particle impact test, in order to quickly evaluate tribological properties of thin, single layered or multilayered hard coatings.(1) By slurry jet 1 μm alumina particles were impacted at high velocity perpendicular to thin PVD coatings of TiN, CrN, TiCN, the coatings proved to have much higher wear resistance than the substrate material, and, consequently, the wear rate increased significantly to the higher level of the substrate material when the coatings were penetrated.(2) By using a slurry jet impact test, fast and highly reproducible evaluation of wear properties of PVD coated drills can be made.(3) The PVD coatings deposited on the drills showed the same wear resistance as those on the plate specimens used as reference samples.(4) For the coatings included in this study, the TiN proved to have the highest wear resistance, whereas the CrN was the worst.(5) The wear resistance of CrNi coatings decrease with increasing the concentration of Ni.(6) The ranking of wear resistance for CrN (CrNi) coatings show good correlation to their micro hardness.We conclude that the proposed evaluation test is fast and easy to accomplish. Thus, it can preferentially be used as a screening test when evaluating coatings and coated tools.