Abstract Dry machining is receiving immense attention worldwide to eliminate or minimize the harmful environmental effects of cutting fluids. The present work investigates dry machining performance of a bilayer coating with top-layer of hard-lubricious TiN–WSx, supported by a hard TiN under layer. During dry turning of AISI 1060 steel, the bilayer coated carbide tool registered significantly less cutting forces as compared to its TiN coated counterpart in the cutting velocity range of 77–230 m/min. In prolonged turning test at cutting velocity of 200 m/min, it also exhibited notably higher tool life on the order of 13 and 2.17 times respectively as compared to the uncoated WC and monolayer TiN coated tool. Such improved performance of bilayer coating was found to be associated with its microstructure, mechanical and tribological properties. Existence of lubricious WS2 phase in the composite TiN–WSx layer along with superior coating adhesion and equivalent nanohardness as compared to TiN resulted in low cutting forces. Formation of W–O tribo layer on surface of worn-out coating on flank surface of tool aided in improving tool life during prolonged turning test.

中文翻译：

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TiN-WSx/TiN硬质润滑双层复合涂层的干车削性能

摘要 为了消除或尽量减少切削液对环境的有害影响，干式加工在世界范围内受到广泛关注。目前的工作研究了双层涂层的干加工性能，该涂层具有硬质润滑 TiN-WSx 顶层，由硬质 TiN 底层支撑。在 AISI 1060 钢的干车削过程中，在 77-230 m/min 的切削速度范围内，双层涂层硬质合金刀具的切削力明显低于其 TiN 涂层刀具。在切削速度为 200 m/min 的长时间车削试验中，与未涂层 WC 和单层 TiN 涂层刀具相比，它的刀具寿命也分别提高了 13 倍和 2.17 倍。发现双层涂层的这种改进性能与其微观结构、机械和摩擦学性能有关。与 TiN 相比，复合 TiN-WSx 层中存在润滑的 WS2 相以及优异的涂层附着力和等效的纳米硬度导致低切削力。在刀具后刀面磨损涂层的表面形成 W-O 摩擦层有助于提高刀具在长时间车削试验中的寿命。