TiAlN/AlON纳米多层涂层的微观结构和力学性能研究

通过磁控溅射制取一系列不同AlON厚度的TiAlN/AlON纳米多层涂层,并用X射线衍射、扫描电镜、高分辨透射电镜和纳米压痕仪分别对微观结构和力学性能进行表征和测量。研究表明:非晶态的AlON在厚度约小于1 nm时,在TiAlN模板作用下转变为晶体结构,并与TiAlN呈共格外延生长,出现超硬效应,当AlON厚度为0.7 nm时,硬度和弹性模量分别最高可达38.1 GPa和385.6 GPa。当AlON厚度超过1 nm时,逐渐转变为非晶结构并且破坏了多层涂层的共格外延生长,硬度随之降低。因此利用这种机制可以制备出力学性能好、耐高温氧化性的刀具涂层,满足现代切削的需要。

Research on Microstructure and Mechanical Properties of TiAlN/AlON Nanomultilayers

A series of TiAlN/ AlON nanomultilayers with various AlON layer thicknesses are synthesized by reactive magnetron sputtering.The microstructure and mechanical properties are evaluated by X-ray diffraction(XRD),scanning electron microscopy(SEM),high-resolution transmission electron microscopy(HRTEM) and nano-indentation.The results reveal that,under the template effect of TiAlN layers,amorphous AlON is forced to crystallize and grows epitaxially with TiAlN layers when AlON layer thickness is below 1 nm,and the nanomultilayer appears superhardness effect with the maximum hardness and elastic modulus of 38.1 GPa and 385.6 GPa when AlON layer thickness is 0.7 nm.As the AlON layer thickness exceeds 1 nm,AlON transforms into amorphous state and breaks the coherent growth of multilayers,resulting in the decrease of hardness and elastic modulus.Therefore cutter protective coatings which possess not only better mechanical properties but also good oxidation resistance at high temperature are synthesized by this mechanism to meet modern cutting.