中文摘要：

使用TiAl合金靶,利用中频反应磁控溅射系统,通过交替改变氮气流量的方法,在高速钢（W18Cr4V）基体上沉积了氮含量周期性改变的AlTiN多层薄膜。利用X射线衍射仪（XRD）、场发射扫描电镜（FE-SEM）和高分辨透射电镜（HRTEM）等方法研究了AlTiN多层薄膜微观组织和结构;AlTiN多层薄膜的力学以及膜基结合性能用纳米压痕硬度仪和划痕试验得到。结果表明,制备的AlTiN薄膜,尽管交替的两层中氮含量不同,但每一单层都为非晶包裹纳米晶的纳米复合结构,所不同的是,低氮含量层中纳米晶密度较小。多层结构的形成能够很大的提高AlTiN多层薄膜的临界载荷和结合能,同时硬度和弹性模量值均有微小的提高,氮气流量的增加有利于多层膜性能的改善。

英文摘要：

The AlTiN composition multilayer coatings were deposited on high speed steel substrates with a medium-frequency （MF） reactive magnetron sputtering system using rectangular TiAl targets. During deposition of AlTiN multilayer thin films nitrogen flux was alternated in different periods. X-ray diffraction （XRD）,Field emission scanning electron microscopy （FE-SEM）,and high-resolution transmission electron microscopy （HRTEM） were used to investigate the microstructure of AlTiN composition multilayer coatings. Their mechanical behaviors and adhesion properties were investigated using nano-indenter and scratch test. The result indicates that the presently deposited multilayer thin films consisted of alternating AlTiN with different nitrogen contents in different layer thicknesses. In each layer,AlTiN exhibits nanocomposites of nanocrystallites embedded into amorphous matrices despite of their nitrogen content. The difference between bilayer is that AlTiN layer with lower nitrogen content has a lower density of nanocrystallites. Formation of multilayer structure greatly increases the critical load at which film-substrate interface delamination occurs and adhesion energy although it only slightly increases both hardness and elastic modulus values,which indicates that formation of multilayer structure is beneficial for improvement of adhesion. Increase of nitrogen flux enhances this effect.