硬质多元氮化物薄膜研究进展

Study Progress of Hard Multicomponent Nitride Films

综述了硬质多元氮化物薄膜的研究进展,主要是从硬质薄膜的发展历程上,介绍了每一代薄膜的产生及其特点。同时介绍了硬质多元氮化物薄膜的结构及其性能特点。着重从如何提高薄膜硬度和韧性方面进行了详细介绍,对几种硬化机制进行了论述,包括晶粒细化、晶界强化、固溶强化及离子轰击/应力硬化。同时还介绍了提高薄膜韧性的方法,包括引入一个韧性相(包括金属相)、利用相变韧化、引入压应力韧化、优化涂层结构等。同时还指出,硬度和韧性都是硬质薄膜获得实际应用的重要指标。单纯追求高硬度或高韧性是不可取的,因为硬质薄膜一般脆性较大,而韧性好的薄膜却缺乏足够的硬度。从工程应用的角度来说,既要得到较高的硬度,而且韧性不能损失太多。最后指出,今后的发展方向要将硬化和韧性的研究集中在纳米尺度上,即如何在纳米尺度上进一步理解薄膜的变形。

Research progress of hard multiple-elements nitride films was reviewed. Production and characteristics of each generation of hard films were introduced in respect of development history of hard films. Structure and performance features of the hard multiple-elements nitride films were elaborated as well. Methods of improving hardness and toughness of the hard films were detailed. Several hardening mechanisms including grain refinement, grain boundary strengthening, solid solution streng- thening and ion bombardment/stress hardening were discussed. In addition, methods of improving film toughness were intro- duced, i.e., introducing a ductile phase （including metallic phase）, using phase transformation toughening, introducing compres- sive stress toughening and optimizing coating structure. It was pointed out that both hardness and toughness were very important indices for practical application of hard films. Pure pursuit of high hardness was inadvisable, because hard coatings usually were brittle and less durable while toughened films were less intensive. In view of practical engineering applications, it was more de- sirable to have films of high hardness without losing too much toughness. Finally, futtre development direction was going to focus on study on the nanometer scale of hardening and toughness, that was, how to further understand film deformation on the nanometer scale .