氮含量对直流磁控溅射(TiAlTaCrZr)N涂层力学及钛合金切削性能的影响

Effect of Nitrogen Contents on Mechanical and Titanium Alloy Cutting Performance of(TiAlTaCrZr)N Coatings by DC Magnetron Sputtering

为了解决传统刀具耐磨涂层导热性差的问题,采用直流磁控溅射方法,在不同氮气流量下制备了(TiAlTaCrZr)N涂层,研究了氮含量对涂层微结构和硬度、结合力、导热等性能的影响。随着氮气流量的增加,涂层中N含量增加,涂层微观结构会由纳米晶向柱状晶转变。涂层的硬度从TiAlTaCrZr涂层的11.0GPa增加到5mL/min氮流量时(TiAlTaCrZr)N涂层的20.6GPa。涂层在氮气流量为5mL/min时的膜基结合力可达到130N以上,之后随着氮含量的增加逐渐降低。(TiAlTaCrZr)N涂层的导热性均优于TiAlN涂层的导热性,但随着氮含量的增加导热性降低。(TiAlTaCrZr)N涂层的高导热性、高结合力、高硬度等特性使其在钛合金高速切削时切削距离比TiAlN涂层提高175%,这为钛合金加工提供了一种新型耐磨涂层。

In order to solve the problem of poor thermal conductivity of traditional tool coatings with high wear resistance,the coatings of(TiAlTaCrZr)N were prepared by DC magnetron sputtering under different nitrogen flow rates.The effects of different nitrogen contents on the microstructure,hardness,adhesion and thermal conductivity of the coatings were studied.With the increase in nitrogen flow rate,the content of N in the coatings increases,and the microstructure of the coatings changes from nanocrystalline to columnar crystal.The hardness of the coatings increases from 11.0 GPa of the TiAlTaCrZr coating to 20.6 GPa of the(TiAlTaCrZr)N coating with 5 mL/min nitrogen flow rate.The adhesion of the coating reaches to the value of 130 N when nitrogen flow is 5 mL/min,and then decreases gradually with the increase in nitrogen content.The thermal conductivity of the(TiAlTaCrZr)N coating is better than that of the TiAlN coating,but it decreases with the increase in nitrogen content.Since the(TiAlTaCrZr)N coating has high thermal conductivity,high adhesion and high hardness,the cutting length of the(TiAlTaCrZr)N coating is 175%higher than that of the TiAlN coating for the titanium alloy cutting.It provides a new tool coating with high wear resistance and high thermal conductivity for titanium alloy cutting.