力反馈伺服滚压在位辅助纳米切削曲表面完整性调控方法

Surface integrity of nano-cutting generated curve surface plays an important role in the development of weapon system and construction of inertial confinement fusion system. However, the manufacturing technology at present, could not satisfy the requirement of them in the nano-cutting of soft metals, such as the homogenization and control of the nano-cutting generated surface integrity, and realization of an integrated manufacturing process combined with high surface integrity and high precision. .In this project, a method, force controlled tool servo rolling, is proposed to realize the in-situ surface modification of soft metals’ complex surfaces at ultra-precision machine tool. Based on this method, the matching issues about the surface modification method with the machining precision of the nano-cutting, could be solved; a homogeneous surface, including surface microstructure, microhardness and residual stress, could be obtained; the machinability of the subsurface of the soft metal could be improved; finally the surface integrity of nano-cutting generated curve surface could be improved by an in-situ modification assisted method..Therefore, the homogeneous modification mechanism of the surface microstructure, microhardness and residual stress of the soft metals should be investigated. The homogeneous modification method of the material’s surface and relevant prediction models should be built. The influences of the surface modified material on the nano-cutting generated surface integrity should be studied. The improvement method and the relevant prediction models about the nano-cutting generated surface integrity should be constructed. Two rolling methods including constant normal direction rolling method and axial force compensated rolling method should be investigated. The method to homogenize and control the nano-cutting generated curve surface integrity by an in-situ force controlled tool servo rolling should be mastered.

纳米切削表面完整性在武器系统研发与激光聚变系统构建中发挥着至关重要的作用，然而，目前尚不能满足它们对软质金属材料纳米切削曲表面完整性的均一化可控制造、以及高表面完整性与高精度的一体化制造需求。本项目拟提出基于力反馈伺服的滚压方法，在超精密加工机床上实现对软质金属材料复杂曲面的在位辅助调控，解决材料表面调控方法与纳米切削精度的匹配问题，获得均一化的表面微观组织、显微硬度和残余应力状态，改善表层材料纳米切削性能，实现对纳米切削曲表面完整性的在位辅助均一化调控。为此，研究基于力反馈伺服的滚压表面材料微观组织、显微硬度以及残余应力均一化调控机制，建立表面材料均一化调控方法与预测模型；研究滚压调控后的材料表面特性对纳米切削表面完整性的影响机制，建立纳米切削表面完整性提升方法与预测模型；研究针对曲面的恒法向滚压以及轴向力补偿滚压方法，掌握基于力反馈伺服滚压在位辅助的纳米切削曲表面完整性均一化制造方法。

一种新的可与超精密加工机床相耦合的表面调控方法，并设计了力反馈伺服滚压工具，被提出用于改善软质材料铅、锡等的纳米切削性能，获得的相关结论如下：.（1）力反馈伺服滚压工具是对滚压工具、快速伺服系统以及力传感器的系统集成，可基于超精密加工机床实现材料的在位恒力滚压调控；.（2）力反馈伺服滚压方法可提高材料表面硬度的同时，在一定程度上减小粗加工表面粗糙度；.（3）表面经过滚压处理后的铅，在纳米切削过程中的表面划痕、刀具刃口处的积屑瘤以及车削过程中的侧流等现象均被抑制。基于力反馈伺服滚压调控方法，可获得铅的镜面级加工，测得的表面粗糙度Ra达5-7nm。处理后铅的切削性能接近纯铝的切削性能；.（4）基于该方法实现了纯锡、纯铅等材料平面镜面，微结构表面的切削，加工效果显著。同时将该方法引入了铝、铜等材料自由曲面的滚压辅助切削，但切削表面质量改善不明显。但发现，滚压处理会形成表面残余应力，合适的、对称的预置内应力，可以提铝、铜等弱刚性件加工时的精度稳定性与可达性。