含氧量对CrAlSiN纳米复合涂层刀具组织结构与性能的影响机制

Nanocomposite coated high-speed cutting tools attact great attentions due to their superhardness and excellent thermal stability. However, the difficulty in reproductivity limited their wide application, which is mainly due to oxygen contamination in the coatings. This project selects the CrAlSiN nanocomposite coated cutting tools, which performed excellent on high-speed machining, as an example to investigate the influence of oxygen content. The coatings containing oxygen from residual gas or from oxygen gas influx will be deposited by a new hybrid high-power impulse plasma-assisted magnetron sputtering. The microstructure, hardness, toughness, high-temperature annealing, high-temperature oxidation and diffusion, wear behavior of the coatings and machining properties of the coated cutting tools will be studied systematically. The influence of oxygen content on the microstructure and mechanical properties of the coatings, the evolution and surface-interface behavior of the coatings in a high-temperature environment, the high-speed machining behavior of the coated tools, will be investigated. The aim of this project is to obtain the theory of producing high-quality nanocomposite coatings coated cutting tools for high-speed machining at low cost, and the related synthesis methods and machining techniques. These results will enrich the theory of nanocomposite coatings and high-speed machining of coated cutting tools. The research will improve the performance of the coatings and lower the request for the coating machine and process, which has very promising applications.

纳米复合涂层刀具因具有超高硬度和优异的高温稳定性受到关注，但性能难以重复限制其普及应用，涂层中氧杂质是主要原因。本项目以具有良好高速切削性能的CrAlSiN纳米复合涂层刀具为代表，采用新型高功率脉冲等离子增强复合磁控溅射技术沉积含氧（残留氧和添加不同含量氧）纳米复合涂层，对涂层的显微结构、硬度、韧性、高温时效、高温氧化和扩散、摩擦、切削加工性能进行系统的研究，获得氧元素对纳米复合涂层的组织结构和机械力学性能影响的规律，涂层在高温环境过程中的组织结构演化规律和表面界面行为，及氧元素影响涂层刀具高速加工性能的行为和机理。本项目的研究目标在于获得高速加工用低成本高性能纳米复合涂层刀具的制备理论、制备方法和加工工艺技术。本项目的研究成果对于丰富纳米复合涂层和涂层刀具切削理论有重要学术价值；项目的研究成果将使得刀具涂层性能得到提升，同时对涂层设备工艺的要求获得降低，有广阔的应用前景。

本项目以具有良好高速切削性能的CrAlSiN纳米复合涂层为基础，沉积含氧和不含氧的CrAlSiN纳米复合涂层，对涂层的显微结构、硬度、高温时效和高温稳定性、摩擦和切削加工性能进行系统研究，获得氧元素对纳米复合涂层的组织结构和机械力学性能的影响规律，涂层在高温环境下的组织结构演化规律，及氧元素影响涂层的刀具高速加工性能的行为和机理。基金工作按照原计划进行，获得了含氧CrAlSiON纳米复合涂层组织结构受涂层中Al、Cr、Si、O、N成分和沉积偏压影响的规律，涂层在高温下和氧化环境下的稳定性和组织结构演化规律，及与此相关的涂层力学性能、摩擦学行为；研究了AlTiN、AlCrN等氮化物刀具涂层的高温稳定性和高速切削行为并对比优化；以此为基础，设计了含AlTiN底层和含氧CrAlSiN纳米复合涂层的多层复合氧氮化物涂层刀具，在高速切削淬硬钢取得良好的效果，并对相关氧元素影响涂层刀具高速切削行为的机理进行了研究。