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

解决传统刀具耐磨涂层导热性差的问题。本文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,研究了不同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11.0 GPa增加到5 SCCM氮流量时(TiAlTaCrZr)N 涂层的20.6 GPa。涂层在氮气流量为5 SCCM时膜基结合力可达到130 N以上,之后随着氮含量增加逐渐降低。(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。

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

In order to solve the problem of poor thermal conductivity of traditional tool coatings with high wear resistance, the (TiAlTaCrZr)N coatings 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 of nitrogen flow rates, 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 SCCM nitrogen flow rate. The adhesion of the coating reaches to the value of 130 N when nitrogen flow is 5 SCCM, and then decreases gradually with the increase of nitrogen contents. The thermal conductivity of the (TiAlTaCrZr)N coating is better than that of the TiAlN coating, but the thermal conductivity decreases with the increase of nitrogen contents. Since the (TiAlTaCrZr)N coating have 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 titanium alloy cutting. It provides a new tool coating with high wear resistance and high thermal conductivity for titanium alloy cutting.