反应磁控溅射TiN/AlON纳米多层膜的微结构与显微硬度

MICROSTRUCTURES AND MICRO-HARDNESS OF TiN/AlON NANOMULTILAYERS SYNTHESIZED BY REACTIVE MAGNETRON SPUTTERING

采用Ti靶和Al_2O_3靶在Ar、N_2混合气氛中进行反应磁控溅射的方法,制备了一系列不同AlON层厚度的TiN/AlON纳米多层膜,利用EDS、XRD、HRTEM和微力学探针研究了AlON的形成条件以及AlON调制层厚的改变对多层膜生长方式和显微硬度的影响.结果表明,在Ar、N_2混合气氛中对Al_2O_3进行溅射,N原子会部分取代Al_2O_3中的O原子,形成非晶态的AlON化合物.在TiN/AlON纳米多层膜中,由于TiN晶体层的模板效应,AlON层在厚度小于0.6 nm时被强制晶化并与TiN形成共格外延生长结构,多层膜显示出最高硬吱达40.5 GPa的超硬效应;进一步增加AlON的层厚,其生长模式由晶态向非晶态转变,破坏了多层膜的共格外延生长结构,多层膜的硬度随之降低.

Ti and Al2O3 targets are used to prepare a series of TiN/AlON nanomultilayers in the gas mixture of Ar and N2 with reactive magnetron sputtering method. The formation conditions of AlON and the effects of thickness of AlON on microstructures and mechanical properties of the multilayers are evaluated and characterized by EDS, XRD, HRTEM and nanoindentation. The investigations show that O atom in Al2O3 will be partially replaced by N atom when sputtering Al2O3 target in the gas mixture of Ar and N2, forming amorphous AlON. In TiN/AlON nanomultilayers, when thickness of AlON is less than 0.6 nm, AlON, due to the template effect of TiN crystal layer, is forced to crystallize and grow epitaxially on TiN, and the multilayers begin to show superhardness effect with a highest HV value of 40.5 GPa. With further increase of the thickness of AlON, its growth mode changes from crystal to amorphous, therefore the epitaxial structure of multilayeres was destroyed and the hardness of multilayers decreased.