基于强电磁过程的纳米陶瓷结合剂高性能CBN砂轮及其磨削性能研究

针对目前国内生产的陶瓷结合剂CBN砂轮普遍存在陶瓷结合剂强度低、脆性大、韧性差、磨粒把持力弱、导热性差、寿命低等问题，本项目提出一种采用强电磁过程材料制备工艺的纳米陶瓷结合剂CBN砂轮的制造方法。在砂轮固化成型过程中通过施加强磁场获得取向组织，提高陶瓷结合剂的强度和磨粒分布的均匀性。采用理论分析、计算机仿真与试验相结合的方法揭示电磁力随形分布、材料塑性流动、扩散复合及组织结构演变等科学规律；研究磁场强度、磁场方向、制备温度、制备时间等工艺参数对陶瓷结合剂取向组织和磨粒分布的影响，获取砂轮最佳成型工艺参数，以制备出磨料分布均匀性好的高性能CBN砂轮；测试分析强电磁过程制备的纳米陶瓷结合剂CBN砂轮的化学、物理、机械性能；试验研究所制备的纳米陶瓷结合剂高性能CBN砂轮加工钛合金等难加工材料的磨削特性，并与普通陶瓷结合剂CBN砂轮进行对比分析，验证利用强电磁过程制备陶瓷结合剂CBN砂轮的先进性。

According to the existing problems of low strength, great brittleness,poor toughness,weak pullout strength and short life of the vitrified bond of CBN grinding wheel in our country, this project puts forward a manufacture method of the nanometer vitrified bond CBN grinding wheel by using the material preparation technology in strong electromagnetic environment. The orientation tissue,which enhances the strength of vitrified bond and uniformity of grain distribution,is obtained in the process of curing molding of the grinding wheel under high magnetic field. This project mainly studies the influence of formation mechanism, the magnetic field intensity,gradient,temperature,time on the orientation tissue of nanometer vitrified bond under strong magnetic field, and reveals the shape follow-up distribution of electromagnetic force, plastic flow of material, diffusion bonding and evolution of structure; the CBN grinding wheel with good uniformity of grain distribution can be obtained by studying the law of the influence of high magnetic field on the grain distribution; the optimum forming parameters can be got through the computer modelling and simulation of molding process of nanometer vitrified bond CBN grinding wheel in strong electromagnetic environment; the reasonable grinding process parameters can be obtained by studying the grinding performances of the difficult-to-cut material such as titanium alloy processed by hypervelocity nanometer vitrified bond CBN grinding wheel in strong electromagnetic environment;the superiority can be verified through a comparative analysis of grinding performances of the nanometer vitrified bond CBN grinding wheel and general vitrified bond grinding wheel.