多弧离子镀制备TiN/TiBN纳米复合涂层的结构和性能

为了满足复合材料高速切削加工的需要,用金属Ti靶和纯TiB2靶作为靶材料,在N2气氛下用多弧离子镀方法制备了TiN/TiBN纳米复合涂层。利用X射线衍射仪(XRD)、X射线光电子能谱仪(XPS)、扫描电子显微镜(SEM)和原子力显微镜(AFM)分析涂层的组织结构、成分和表面形貌;利用显微硬度计、划痕仪和球盘摩擦仪分析调制周期对涂层力学性能的影响。结果表明:TiN/TiBN纳米复合涂层的调制周期范围为5.5~21nm,主要成分为晶相TiN、非晶BN和TiB2;调制周期对涂层的力学性能有较大的影响,随着调制周期的减小,硬度增加,调制周期最小时最大硬度达到29GPa;最大膜基结合力为88N,且所有样品均表现出较高的膜基结合力。随着转速的增大,摩擦因数与表面粗糙度两者表现出相同的变化趋势,摩擦因数最大值为0.31,其低摩擦因数与自润滑的BN相的存在有关。调制周期减少,界面积增加,TiN/TiBN纳米复合涂层的力学性能增强。

Structure and Mechanical Properties of TiN/TiBN Nanocomposite Coatings Deposited by Multiarc Plasma Deposition

In order to meet the requirement of high speeding cutting machining of composite materials, TiN/TiBN composite coatings were synthesized on the substrates through cathodic multiarc plasma deposition system with Ti and pure TiB2 targets. The structure, composition and surface morphology of the coating were analyzed by Xray diffraction (XRD), Xray photoelectron spectroscopy, scanning electron microscope (SEM) and atomic force microscope (AFM). The microhardness tester, scratch tester and ballondisk friction tester were applied to research the relationships between bilayer period and mechanical properties. The results indicate that the dominated components in TiN/TiBN are crystal TiN, amorphous BN and TiB2, and the scale of bilayer thicknesses is from 5.5 nm to 21 nm. The microhardness increases with decreasing bilayer period, and the highest microhardness reaches 29 GPa. The highest adhensive force is 88 N and all coatings perform perfect adhensive force. Therefore, the bilayer period shows significant influence on mechanical properties. The friction coefficient and surface roughness display the same variation trend. The highest fiction coefficient is only 0.31. The production of selflubrication BN phase is the main reason for the low fiction coefficient value. The smaller the bilayer thickness is, the more the interfaces contribute to improve the mechanical properties.