Abstract Ultra-thin diamond-like carbon (DLC) coatings are used in many engineering applications including hard disk drives, automobile engines, and MEMS/NEMS devices to protect delicate substrates against wear and corrosion. However, they are susceptible to brittle cracking and delamination due to high intrinsic stress and poor adhesion to many substrates. Inclusion of an intermediate layer can prevent delamination of the coating. We perform simple shear and tension loading and nanoscratch molecular dynamics simulations to quantify the effect of coating layer thickness and composition on the adhesion of the ultra-thin multi-layer DLC coatings used in hard disk drives to their substrate. We observe that an intermediate Si layer improves adhesion of DLC coatings to Ni substrates compared to coatings without one, and that an optimum thickness of the Si layer exists. We also find that an intermediate DLC layer with sp 3 fraction lower than the outermost DLC coating layer protects the substrate from plastic deformation under external loading, and that it improves adhesion to Si but not Ni substrates compared to coatings with no intermediate layer.

中文翻译：

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使用剪切、张力和纳米划痕分子动力学模拟量化超薄多层 DLC 涂层对 Ni 和 Si 基材的附着力

摘要 超薄类金刚石碳 (DLC) 涂层用于许多工程应用，包括硬盘驱动器、汽车发动机和 MEMS/NEMS 设备，以保护精密基材免受磨损和腐蚀。然而，由于高内应力和对许多基材的粘附性差，它们容易发生脆性开裂和分层。包含中间层可以防止涂层分层。我们执行简单的剪切和张力载荷以及纳米划痕分子动力学模拟，以量化涂层厚度和成分对硬盘驱动器中使用的超薄多层 DLC 涂层与其基材的附着力的影响。我们观察到，与没有涂层的涂层相比，中间的 Si 层提高了 DLC 涂层对 Ni 基材的附着力，并且存在最佳的硅层厚度。我们还发现，具有比最外层 DLC 涂层低的 sp 3 分数的中间 DLC 层可保护基材免受外部载荷下的塑性变形，并且与没有中间层的涂层相比，它提高了对 Si 基材的附着力，但不能提高对 Ni 基材的附着力。