Evaluation of tribological properties of advanced thin hard coatings and acceralated wear test.

为了快速评价薄层、单层和多层涂层的摩擦学性能，我们提出了一种新型的固体颗粒冲击试验--浆料射流。(1)研究了冲击角、冲击压力、浆料浓度和腐蚀剂尺寸对沉积在高速钢基材上的PVD TiN磨损的影响。(2)利用浆料射流，在垂直于TiN、TiN/NBN、TiN/TaN、TiN/CrN、TiN/TiAlN薄层的PVD涂层上高速冲击氧化铝颗粒，涂层的抗冲蚀性能明显高于基体材料，从而使涂层的磨损率显著提高到高速钢材料的较高水平。(3)CrNi涂层的耐磨性随Ni含量的增加而降低。(4)软DLC涂层在涂层与基材的弱界面处发生断裂。硬质类金刚石涂层局部断裂，基材暴露。(5)我们得出结论，所提出的评价测试快速且易于实现。因此，在评价涂层和涂层材料时，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 coatings.(1) The effects of impact angle, impact pressure, concentration of slurry and erodent size on the wear of PVD TiN deposited on a high speed steel (HSS) substrate material were clarified. It was also found that maximum depth on the scar is suitable to evaluate wear properties and our test method generates reproducible results.(2) By slurry jet 1 um alumina particles were impacted at high velocity perpendicular to thin PVD coatings of TiN, TiN/NbN, TiN/TaN, TiN/CrN, TiN/TiAlN, the coatings proved to have much higher erosion resistance than the substrate material, and, consequently, the wear rate increased significantly to the higher level of the HSS material when the coatings were penetrated. The ranking of erosion resistance and correlation to the mechanical properties, such as hardness and critical normal load obtained by scratch testing are discussed.(3) The wear resistance of CrNi coatings decrease with increasing the concentration of Ni.(4) Soft DLC coating fractures at the weak interface between coating and substrate material. Hard DLC coating fractures locally and thus substrate exposes.(5) 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 materials.