AlTiN、AlTiN-Cu和AlTiN/AlTiN-Cu涂层的微观结构、力学性能及铣削性能

摘要

采用阴极弧蒸发沉积技术在WC-6%Co基体上制备AlTiN、AlTiN-Cu和AlTiN/AlTiN-Cu涂层,采用2种氮气压力制备 AlTiN-Cu和AlTiN/AlTiN-Cu涂层:2.2 Pa和3.2 Pa.利用扫描电镜观测涂层的表面形貌和截面形貌,结合X射线衍射谱和X射线光电子能谱确定涂层成分和晶体结构,利用纳米压痕划痕仪测定涂层的硬度和膜基结合力.在相同条件下,进行湿式铣削 TC4试验,对比研究5种涂层刀具的铣削性能.研究结果表明,添加 Cu 后,AlTiN 涂层表面液滴增多,晶粒细化,硬度降低但耐磨性提高.当N2压力由2.2 Pa增大到3.2 Pa时,AlTiN-Cu和AlTiN/AlTiN-Cu涂层晶粒尺寸细化,硬度提高但是膜基结合力下降.在相同N2压力下,AlTiN-Cu和AlTiN/AlTiN-Cu涂层刀具铣削寿命分别较AlTiN涂层刀具的提高11% 和 24%.%AlTiN, AlTiN-Cu and AlTiN/AlTiN-Cu coatings were prepared on WC-6%Co substrates by cathode arc evaporation deposition technology. Two kinds of nitrogen pressures were used to deposit both AlTiN-Cu and AlTiN/AlTiN-Cu coatings. Surface and cross-sectional morphologies of films were observed by scanning electron microscopy (SEM). Crystal structure of films was analyzed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Hardness and adhesion of films were measured by nano-indentation and nano-scratch tester. Cutting tests were performed under milling conditions during wet machining of TC4 alloy. The results show that with addition of Cu, more droplets occur on AlTiN coating surface, but the grain size of it is refined, and the hardness decreases but the toughness is improved. Under higher N2pressure, the defects on the surface of AlTiN-Cu and AlTiN/AlTiN-Cu coatings diminish, and the hardness of them is enhanced, while the adhesion is reduced. Compared to AlTiN coated cemented carbide tool, the lifetimes of AlTiN-Cu and AlTiN/AlTiN-Cu coated tools under the same N2 pressure are improved by 11% and 24%, respectively.