面向硬脆材料超精密加工的树脂磨具快速成型方法及其磨削机理研究

Based on the demand of ultra-precision machining technology for hard brittle materials, this project proposes a new technology of real-time hybrid 3D printing light curing process of the resin-bonded precision abrasive tool under multi-field coupling of light, temperature, and stress. Combined with the theory of impact kinetics, tribology, thermodynamics, fracture mechanics, the unique abrasive wear mechanism of the above-mentioned abrasive tool is comprehensively studied. First of all, based on the light absorption characteristics and photochemical chain-polymerization reaction level in the resin binder-abrasive matrix, a preconditioning stress model for single abrasive grain in the resin bonded matrix is developed; Further, the abrasive wear mechanism, in which fixed abrasive and loose abrasive transform into each other and work together, is revealed. An abrasive grain working state prediction model is established and validated through the wear test of diamond abrasive resin bonded tool; On this basis, in view of the plastic removal, plastic deformation, brittle removal and other surface formation mechanism during the ultra-precision abrasive machining of hard brittle materials, a Monte Carlo analysis integrated model considering the random uncertainty of abrasive distribution, morphology, and working condition is proposed to predict material removal rate and surface roughness; It is hoped that the final establishment of “Tool fabrication process-Abrasive machining mechanism-Surface formation mechanism” interconnected research system will effectively promote the development of ultra-precision machining technology.

本项目以硬脆材料超精密加工技术需求为背景，提出一种在光照、温度、应力等多场耦合作用下，实现树脂结合剂精密磨具快速成型的多材料即时混合3D打印光固化工艺方法，并结合冲击动力学、摩擦学、热力学及断裂力学等理论对此类磨具独特的磨削机理进行深入研究。首先，根据光在树脂结合剂-磨料混合基体中的吸收特性及光化学链式聚合反应完成度建立固化磨具中磨粒预受力状态模型；进而，结合金刚石磨料树脂磨具磨损实验掌握此类磨具磨削过程中固结磨料与游离磨料相互转化、共同作用的独特磨削机制；在此基础上，针对硬脆材料超精密磨削过程中的塑性去除、塑性变形、脆性去除等表面形成机理，依据蒙特卡罗分析方法建立考虑磨料分布、形貌及工作状态随机不确定性的材料磨除速率及表面粗糙度预测模型；最终构建“磨具成型方法-磨料磨削机制-表面形成机理”各部分相互关联的完整研究体系，为超精密加工技术的发展提供有效支撑。

本项目以硬脆材料超精密加工技术需求为背景，提出一种在光照、温度、应力等多场耦合作用下，实现树脂结合剂精密磨具快速成型的多材料即时混合3D打印光固化工艺方法，并结合冲击动力学、摩擦学、热力学及断裂力学等理论对此类磨具独特的磨削机理进行深入研究。首先，根据光在树脂结合剂-磨料混合基体中的吸收特性及光化学链式聚合反应完成度建立固化磨具中磨粒预受力状态模型，并基于冯洛诺伊图案特征随机网格结构设计方法实现了光固化树脂结合剂金刚石磨料磨具的实验室制备，结合图像数值分析与磨削轨迹仿真对其加工性能进行了验证；进而，结合金刚石磨料树脂磨具磨损实验掌握此类磨具磨削过程中固结磨料与游离磨料相互转化、共同作用的独特磨削机制，并对树脂结合剂金刚石磨具磨削过程中单颗磨粒失效行为机制进行了深入探究，建立了基于树脂结合剂快速成型工艺参数与磨料颗粒形状特征的固结把持失效分析模型；在此基础上，本项目针对硬脆材料超精密磨削过程中的塑性去除、塑性变形、脆性去除等表面形成机理，以碳化硅为具体研究对象，通过SPH方法分析了磨削过程中磨削速度、磨削深度、磨削力等关键参数对材料去除效率与表面完整性的影响；本项目的顺利执行完善了“磨具成型方法-磨料磨削机制-表面形成机理”各部分相互关联的系统研究体系，为以磨削、抛光等工艺方法为代表的超精密制造新方法、新工艺的发展提供一定的理论支撑与技术参考。