沉积温度对纳米ZrN涂层结构及性能的影响

Effect of Deposition Temperature on Structure and Mechanical Properties of ZrN Nano-coatings

利用磁控溅射方法通过改变沉积温度(Ts)制备一系列纳米ZrN涂层.采用X射线衍射、扫描电镜及CSM纳米力学综合测试系统表征了纳米ZrN涂层的物相结构、截面形貌及综合力学性能,系统研究了沉积温度对纳米ZrN涂层结构及性能的影响.实验结果表明:随着沉积温度的增加,涂层择优取向由(111)变为(200),而在600℃时结晶度很低;涂层择优取向的变化是由涂层沉积过程中原子迁移能力和不同取向表面能的差异所决定的.纳米ZrN涂层在Ts=450℃及以下温度区间为柱状结构,并随沉积温度增加柱状晶逐渐变宽,在Ts=600℃时,由于生长方式的改变使涂层变为非柱状等轴结构.纳米ZrN涂层的硬度在Ts=450℃及以下温度区间没有明显变化,但在Ts=600℃时,由于涂层结晶度以及位错密度降低导致涂层硬度下降.随沉积温度的增加,涂层与基体间结合力先减小后增大.纳米ZrN涂层的磨损率由硬度和膜基结合力共同作用决定.

The influence of deposition temperature on microstructure and mechanical properties of ZrN nano-coatings fabricated by DC magnetron sputtering was investigated.X-ray diffraction,scanning electron microscope and CSM-instruments were applied to characterize the phase structure,morphologies of cross-section and mechanical properties of ZrN nano-coatings.It is showed that with the increasing of the deposition temperature the preferred orientation of the coating changes from（111） to（200）,and the peak intensity was too weak to detect at 600 ℃ for the quite low crystallinity of the coating.The preferred orientation of the caoting depends on the surface adatom migration during deposition process and the difference of surface energy between different orientations.From 50 ℃ to 450 ℃,the coatings showed columnar structure,and the columnar width rised with the temperature′s increasing,while at 600 ℃ the columnar disappeared,presenting equiaxed structure instead.The hardness of coatings showed few significant variations under 450 ℃,and at 600 ℃ the coating hardness dropped for the low crystallinity and the decreasing of dislocation density.The adhesion between the coating and substrate decreased with the increasing of temperature before 450 ℃,then increased at 600 ℃.The wear rate of ZrN nano-coating depends on the interaction of hardness and adhesion of coatings.