Abstract Using a combined pretreatment of sand-blasting and two-step etching, nanocrystalline diamond coatings with primarily diamond crystallites and good adhesion were deposited onto carbide cement by tuning the Ar/H2 ratio in the hot filament chemical vapor deposition (HFCVD) work gas. The microstructure, bonding structure, surface morphology and roughness, and wear scar were characterized using a scanning electron microscope, an atomic force microscope, a white light interferometer, and a Raman spectrometer. The dry sliding behavior of the coating against Si3N4 was tested using a pin-on-disc instrument. It was found that the addition of Ar to the HFCVD work gas can enhance grain refinement and tune the morphology of the nanocrystalline coatings. The roughness was reduced from 87.7 nm for the coating prepared without Ar to 6.21 nm for the coating prepared with 90% Ar. With the addition of Ar, the friction coefficient and wear rate decrease monotonically. The wear rate of the coating prepared with 90% Ar was less than 5% that of the coating prepared without Ar, and the wear mechanism transforms from spallation to be limited by the stress-induced sp2 tribo-layer.

中文翻译：

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含Ar工作气体对纳米晶金刚石涂层微观结构及摩擦学行为影响的研究

摘要 使用喷砂和两步蚀刻的联合预处理，通过调整热丝化学气相沉积 (HFCVD) 工作气体中的 Ar/H2 比，在碳化物水泥上沉积主要具有金刚石微晶和良好附着力的纳米晶金刚石涂层。使用扫描电子显微镜、原子力显微镜、白光干涉仪和拉曼光谱仪对微观结构、结合结构、表面形貌和粗糙度以及磨痕进行表征。使用针盘式仪器测试涂层对 Si3N4 的干滑动行为。研究发现，向 HFCVD 工作气体中添加 Ar 可以增强晶粒细化并调整纳米晶涂层的形态。粗糙度从不含 Ar 制备的涂层的 87.7 nm 降低到 6 nm。用 90% Ar 制备的涂层为 21 nm。随着Ar的加入，摩擦系数和磨损率单调下降。含 90% Ar 制备的涂层的磨损率小于不含 Ar 制备的涂层的 5%，磨损机制由剥落转变为受应力诱导的 sp2 摩擦层的限制。