多元多尺度仿生自修复刀具及其增效机理研究

The multiple multi-scale and biomimetic self-repair theory are used for system design of coating tool and tribology design. According to the actual lubrication condition, the self-repair cutting tool can be designed and fabricated by the reasonable structure and materials configuration of cutting tool and the micro/nano self-repair particles in lubricant. It is expected that the tool wear could be repaired with different processing parameters in the actual cutting conditions. So, we can maximize the cutting tool life and improve the machining efficiency to the limit. Base on the design and preparation of high coating tool, the microstructure, the self-repair effect of micro/nano particles, friction and wear and cutting characteristics, multi-phase, multi-scale and self-repair theory method are used to build the best matching combination in the different types of the tool and workpiece for self-repair machining. Considering the local high load of coating tool and self-repair characteristics of nano biomimetic materials, we can obtain the best lubricant and structure system of self-repair cutting tool, multi-phase and multi-scale description of tribology system for self-repair cutting, and the optimized parameters of fabrication the self-repair cutting tool and machining process in different lubrication conditions. In conclusion, we design and the development a suitable self-repair cutting tool for machining of difficult-to-cut materials, this project reveals the wear and repair rule of self-repair cutting tool in multi-phase and multi-scale, which provides a theoretical and technical basis for the effective solution in improving the tool life and efficiency of difficult-to-cut materials machining.

本项目将多元多尺度与仿生自修复理论用于涂层刀具的系统设计和摩擦学设计中，根据实际的润滑工况，合理设计刀具的结构与材料，配合润滑剂中的微纳米自修复颗粒，在优化的工艺条件下，有望实现刀具的磨损随着不同加工参数而实时修复，最大限度的提高切削刀具的寿命和加工效率。以加工中的高端涂层刀具设计与制备、微观结构、微纳米颗粒自修复、摩擦磨损、切削特性等为研究对象，采用多元多尺度和自修复的理论手段，充分考虑涂层刀具切削时的高负荷和纳米仿生材料的自修复特性，通过建模与试验研究手段获得自修复加工中不同类型的刀具、润滑剂的最佳匹配组合；最优的自修复刀具材料和结构体系；自修复切削摩擦系统的多元多尺度描述；自修复刀具制备及各种润滑工况下最优的工艺参数。设计并开发出适合切削难加工材料的自修复刀具，揭示出多元多尺度下的自修复刀具的磨损与修复规律，为有效解决切削难加工材料中刀具寿命和加工效率偏低的难题奠定理论与技术基础。

本项目将多元多尺度和仿生自修复理论应用于涂层刀具的系统设计中,设计并开发出适合切削难加工材料的自修复刀具，为有效解决切削难加工材料中刀具寿命和加工效率偏低的难题奠定理论与技术基础。项目按原定计划顺利地开展了研究，并且取得了较好的成果，重要进展主要为以下四个方面：. (1) 多涂层自修复刀具的制备与自修复控制技术。. 对于不同类型的复合双梯度自修复涂层，制备后的涂层热残余应力明显小于CrN和ZrN单涂层，复合双梯度涂层的结合力明显好于单涂层，最终制备出从内部的高塑性Cr/CrN长梳状层逐渐过渡到外部的A1ZrCrN短粗状高耐磨层的合理涂层结构。. (2) 仿生自修复刀具涂层的设计理论。. 针对高效干切削和微量润滑加工中润滑能力不足的难题，利用自修复膜表面的活性，将自润滑性能良好的石墨烯粒子组装在其表面，以降低表面自由能。不仅可以大幅度提高刀具的抗磨性和寿命，而且其转移膜对已加工表面可以起到关键的保护作用。. (3) 偏析生长法制备石墨烯仿生自修复涂层。.从涂层结构设计要求上看，GP1115表面的涂层是由于硬质合金刀具基体脱碳的结果，原GP1115表面的复合涂层有利于形成较致密均匀的石墨烯薄膜，脱碳现象有利于提高刀具的抗崩刃能力，增加涂层刀具的抗冲击韧性。CA5525石墨烯仿生涂层在刀具表面制备过程中出现了枝状生长，可以观察到主干和分枝的晶型一样，且取向基本一致。虽然整个树枝状结构不是一个单晶，但它有一定形式的最优晶体取向。随着反应时间的增长形貌并没有太大的变化，表明石墨烯的树枝状结构的形成是一个快速的过程。通过偏析生长法制备出MT-TiCN+Al2O3+TiN+Graphene的复合多梯度涂层刀具。. (4) 化学气相沉积法制备石墨烯仿生自修复涂层。.刀具表面涂层是复合多涂层，即MT-TiCN /Al2O3/ Graphene非晶碳复合多涂层。最外面附着银白色的非结晶体碳（玻璃碳），石墨烯涂层次之。通过控制碳源甲烷的溶度和气体流速，可以获得梯度石墨烯非晶碳复合涂层。