轻薄轴承强化研磨加工及表面残余应力形成机理

项目名称： 轻薄轴承强化研磨加工及表面残余应力形成机理

项目编号： No.50875052

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 刘晓初

作者单位： 广州大学

项目金额： 35万元

中文摘要： 本项目提出了集强化塑性加工和研磨微切削为一体的“#24378;化研磨加工”#26032;加工方法加工轻薄轴承套圈，并研究基于三维、湍流、液固加工过程中弹塑性变形和机械化学效应以及表面残余应力形成机理。针对轻薄轴承套圈加工刚性差易变形和跳动的特点，还提出了通过滚桶的高速自转带动工件旋转生产的离心效应来提高套圈动态加工刚度的新技术方案；建立液固两相流动力学模型，弄清磨料流态特性和工艺参数之间的关系及其对加工质量的影响；实验测定表面残余应力分布，并通过正交实验确定合理工艺参数，分析强化研磨加工对表面残余应力、硬化层、金相组织、表面粗糙度的影响，观察工件表面是否形成有利于耐磨损的“#27833;囊”#24418;貌，是否会产生过冷作硬化；运用耗散结构理论，建立结构稳定性和突变过程的数学模型。

中文关键词： 轻薄轴承；强化研磨；耗散结构；残余应力；液固两相

英文摘要： The project proposed a set of Enhanced plastic working and grinding micro-cutting as a new " Strengthening-Polishing " processing method of processing thin bearing rings, and did a research on the basis of three-dimensional elastoplastic deformation in the process of turbulent and liquid-solid machining, mechanical ,chemical effect and formation mechanism of surface residual stress.Aiming at the feature that the poor rigidity, easily deformation and runout tolerances of bearing rings, it also presented a new technical solution to improve dynamic stiffness of the bearing ring, which is achieved by the centrifugal effect of the revolving workpiece that droved by a high-speed drum spin. The liquid-solid two-phase flow mechanical model was established. The relationship between abrasive flow performance and process parameters and their impact on the processing quality were cleared. Surface residual stress distribution was experimentally determined, and reasonable process parameters were determined by orthogonal experiments，which were used to analyze the impact of enhanced grinding on the surface residual stress, hardened layer, microstructure, and surface roughness. The formation of the beneficial wear-resistant "oil bag" morphology on the workpiece surface, and the emergence of over-cold hardening on the surface can also be observed through that. Applying the dissipative structure theory to establish the structural stability and mutation mathematical model.

英文关键词： thin bearing; Strengthening-Polishing; dissipative structure; residual stress; liquid-solid two-phase