论文部分内容阅读
以TiN、TiAlN为主的过渡族金属氮化物硬质涂层以其较高的表面硬度、良好的耐磨以及抗高温氧化性能,被广泛应用于材料表面防护涂层。然而,涂层内部积聚的高内应力却容易引发涂层与基体的结合力问题。利用PVD技术很难在材料表面制备出厚度超过10μm的TiN或TiAlN涂层。多层复合结构能够有效控制涂层中的应力分布,从而使得其成为获得较厚硬质涂层的一种有效方法。本工作在TC4合金以及Si(100)基体上利用等离子增强离子镀技术制备了具有不同复合层数的多层Ti/TiN涂层,并研究了复合层数对涂层力学性能的影响。结果表明,随着复合层数的增加,涂层的各项力学性能得到了显著强化。涂层的显微硬度HV0.25高达27500 MPa,厚度大于50μm,且具有较好的韧性。涂层的韧性与显微硬度成正比例关系。同时,48层复合结构的Ti/TiN涂层具有低于0.35的摩擦系数以及最佳的抗磨损性能。然而,随着复合层数的进一步增加,涂层与基体的界面结合强度显著弱化。
TiN, TiAlN-based transitional group metal nitride hard coatings with its high surface hardness, good wear resistance and high temperature oxidation resistance, is widely used in the protective coating of the surface of the material. However, the high internal stress that accumulates inside the coating tends to cause problems with the bond of the coating to the substrate. It is very difficult to prepare TiN or TiAlN coatings with a thickness of more than 10μm on the surface of the material by PVD technology. The multi-layer composite structure effectively controls the stress distribution in the coating, making it an effective method of obtaining thicker, hard coatings. In this work, multilayer Ti / TiN coatings with different composite layers were prepared by plasma enhanced ion plating on TC4 alloy and Si (100) substrate. The effects of composite layers on the mechanical properties of the coatings were also studied. The results show that with the increase of the number of layers, the mechanical properties of the coating have been significantly enhanced. The coating microhardness HV0.25 up to 27500 MPa, thickness greater than 50μm, and has good toughness. The toughness of the coating is directly proportional to the microhardness. In the meantime, the Ti / TiN coating of a 48-layer composite structure has a coefficient of friction of less than 0.35 and an optimal wear resistance. However, with the further increase in the number of layers, the interfacial bonding strength between the coating and the substrate is significantly weakened.