工作气压对TiBN/TiAlSiN纳米多层涂层的结构和性能影响

为应对高速干式切削、工磨具行业对新型防护涂层的需求,制造高硬度、耐摩擦磨损的纳米复合涂层具有巨大的市场前景。 采用阴极多弧离子镀技术,在不同的工作气压下用 TiB2 和 TiAlSi 合金靶作为阴极蒸发靶材,在硬质合金衬底上分别沉积了 TiBN,TiAlSiN 涂层和 TiBN/ TiAlSiN 多层涂层。 借助于 XRD、 XPS、 SEM、 AFM 和 HRTEM 对涂层的成分、形貌及微观结构进行表征分析。 并用纳米压痕硬度计和球盘式摩擦测试仪分别研究了涂层的硬度和摩擦磨损性能。 研究结果表明:TiBN/ TiAlSiN 涂层呈现一种非晶相包裹纳米多晶相的微观结构形态,工作气压越高,涂层表面越趋于光滑;涂层在 1. 0 Pa 工作气压下涂层显微硬度值达到 38 GPa;在 2. 0 Pa 的工作气压下,涂层显微硬度值约 34 GPa,摩擦因数低于 0. 29。 与 TiBN 和 TiAlSiN 涂层相比,TiBN/ TiAlSiN 纳米多层涂层的机械、摩擦学性能更加优越,这为应用在干式切削、磨削工具领域的硬质润滑多层涂层的制备与研究指明了一条方向。

Effects of Working Pressure on Microstructure and Properties of TiBN/ TiAlSiN Nano-multilayer Coatings

The novel nanocomposite coatings have become the most promising protective materials due to their high hardness and antiwear properties for the requirements of high-speed dry cutting and grinding tool industry. The monolithic TiBN, TiAlSiN and TiBN/ TiAlSiN nano-multilayer coatings were deposited on hard alloy matrixes at various working pressures by tuning N2 flow rates using a cathodic multi-arc ion plating system wherein the composite TiB2 and TiAlSi targets were selected as evaporative cathodes. The microstructure, composition, and morphologies were analyzed by XRD, XPS, SEM, AFM and HRTEM, respec- tively. Nano-indentation and ball-on-disc friction tester were used to investigate the mechanical and tribological properties of the coatings. Results show that TiBN/ TiAlSiN coatings possess a typical structure where the nanocrystals are imbedded in the amor- phous layers. The higher the working pressure, the smoother the surface of TiBN/ TiAlSiN coatingsis. The maximum microhard- ness value can reach 38 GPa at 1. 0 Pa, while a microhardness of approximately 34 GPa with the lowest coefficient of friction of 0. 29 is obtained for TiBN/ TiAlSiN coatings fabricated at 2. 0 Pa as compared to the monolithic TiBN and TiAlSiN coatings with the hardness beneath 28 GPa and coefficient of friction over 0. 50. The mechanical and tribology performance is superior to themonolithic TiBN or TiAlSiN coatings, which can pave the way for fabricating the hard / lubricant nanosized multilayered coatings in the field of dry-cutting and grinding tools.