单晶材料纳观尺度切削去除机理及亚表面损伤抑制方法研究

The revealment of material removal mechanism at nano scale and the establishment of subsurface damage suppression method have important influences on developing the controllable nano-cutting technology with high efficiency and low damage. Because the transient process of material removal is difficult to characterize, it is necessary to further study the nano-cutting mechanism. Therefore, several research contents are put forward as follows: 1) Based on the online observation technology by a scanning electron microscopy, the removal process of single crystal materials at nano scale could be observed during the nano-cutting tests. Explore the size effect in the process of nano-cutting, study the rule of synergistic action of cutting force, cutting edge and cutting thickness on the material removal behaviour. 2) Investigate the influence factors and distribution of the subsurface damage, such as crystalline evolution, phase transition, residual stress and micro cracks. so that the cutting parameters can be clear and definite to reduce the subsurface damage. Meanwhile, based on the mechanical model of nanoindentation, the extrusion model of nano-cutting will be established. 3) Adopt the method of combining the theoretical simulation and experiments, analyze the effect of ion implantation on the surface modification of single crystal material, and study the ion implantation parameters for maximum inhibition of subsurface damage. Moreover, establish the effective method and technology of ion implantation for suppressing the subsurface damage of single crystal materials. This project provides a reference and theoretical basis for improving the manufacturing integrity of nano-cutting, and has important theoretical and practical value.

纳观尺度材料去除机理的揭示和亚表面损伤抑制方法的建立对发展高效率、低损伤的可控纳米切削技术有重要影响。针对目前材料去除的瞬态过程不易表征、对切削机理研究不够深入的问题，提出如下研究内容：1）以扫描电子显微镜在线观测技术为手段，实时观察单晶材料在纳观尺度下的切削去除行为，探索纳米切削过程中的尺寸效应，研究切削力、刀具刃口、切削厚度对材料去除行为的协同作用规律；2）研究纳米切削过程中晶态结构演变、相变、残余应力、微裂纹等亚表面损伤的影响因素和分布规律，明确降低亚表面损伤的切削工艺参数，结合纳米压痕、断裂等成熟的力学模型，建立纳米切削推挤去除模型；3）采用理论模拟和实验相结合的方法，分析离子注入对单晶材料表面改性的影响规律，研究最大程度抑制亚表面损伤的离子注入参数，建立单晶材料纳米切削亚表面损伤的有效抑制方法与工艺。本项目为提高纳米切削制造完整性提供参考和理论依据，具有重要的理论和应用价值。

纳观尺度材料去除机理的揭示和亚表面损伤抑制方法的建立对发展高效率、低损伤的可控纳米切削技术有重要影响。针对目前材料去除的瞬态过程不易表征、对切削机理研究不够深入的问题，本项目研究了如下内容：1）以扫描电子显微镜在线观测技术为手段，实时观察单晶材料在纳观尺度下的切削去除行为，探索了纳米切削过程中的尺寸效应，研究了切削力、刀具刃口、切削厚度对材料去除行为的协同作用规律；2）研究纳米切削过程中晶态结构演变、相变、残余应力、微裂纹等亚表面损伤的影响因素和分布规律，明确降低亚表面损伤的切削工艺参数；3）采用理论模拟和实验相结合的方法，分析了离子注入对单晶材料表面改性的影响规律，明确了最大程度抑制亚表面损伤的离子注入参数，建立了单晶材料纳米切削亚表面损伤的有效抑制方法与工艺。本项目为提高纳米切削制造完整性提供参考和理论依据，具有重要的理论和应用价值。