纳米陶瓷结合剂CBN砂轮微波烧结机理及磨削性能研究

According to the existing problems of high refractoriness, low strength, great brittleness , long sintering time, low strength, weak abrasive grip strength, poor thermal conduct, short life of the vitrified bond of CBN grinding wheel. This project puts forward a manufacture method for the nano-vitrified bond CBN grinding wheel by using microwave sintering preparation technology. In the wheel sintering process, by applying a microwave field on nano-vitrified bond grinding wheel patch, reduce heat stress inside bond to obtain stability structural of nano- whiskers inside the vitrified bond, further exacerbate the potential of nano -micron grain effect in the bond, thus achieve such as the good performance of vitrified bond grain refinement, sintering time shorten, organizations toughened, and the sintering temperature lowered. This project mainly studies the mechanism of nano-vitrified bond microwave sintering process.Try to reveals the crystal structure evolution law and toughen mechanism of nano-vitrified bond. Study influence of microwave sintering power, temperature, heating time, nano-oxides content and other process parameters on performance of the grinding wheel bond and abrasive. Search and formation of high performance grinding wheel preparation new technology and theory.The grinding performance of nano-vitrified CBN grinding wheel under microwave sintering process will be studying by the grinding performances of the difficult-to-cut materials, furthermore to verify the superiority of the new wheel.

针对陶瓷CBN砂轮生产中结合剂耐火度高、强度低、脆性大、烧结时间长、成品率低、磨料把持力弱、砂轮导热性差、使用速度及寿命低等问题,提出一种采用微波烧结工艺过程制备高性能纳米陶瓷结合剂CBN砂轮的方法。通过对纳米陶瓷砂轮贴片在烧结过程中施加微波场，降低结合剂内部热应力获得结构稳定的纳米晶须，进一步加剧结合剂内微米晶粒潜在纳米化效应，从而达到细化晶粒、缩短烧结时间、强韧化组织、降低烧结温度等效果。采取理论、仿真与试验相结合方法，揭示纳米陶瓷结合剂微波烧结机理，分析其纳米强韧化过程及组织结构演变规律，研究微波烧结功率、温度、时间、纳米氧化物含量等工艺参数对砂轮组织、强度、耐火度和磨料性能的影响，探求并形成高性能磨具制备新技术及理论。研究经微波烧结过程纳米陶瓷结合剂CBN砂轮对于典型难加工材料的磨削性能及特点，验证新型砂轮的优越性。

针对陶瓷CBN砂轮传统烧结过程结合剂耐火度高、强度低、烧结时间长、热均匀性差、成品率低等问题，首先出一种采用微波烧结工艺过程制备高性能纳米陶瓷结合剂CBN砂轮的方法。采取理论、仿真相结合方法，揭示了纳米陶瓷结合剂微波烧结过程机理，研究了纳米陶瓷结合剂CBN砂轮微波烧结过程功率、介电损耗、试件位置等因素对电磁场分布、温度场分布以及烧结时间的影响规律，从而优化了微波烧结工艺。进一步进行微波烧结纳米陶瓷结合剂CBN砂轮制备实验，研究了微波烧结过程相关工艺参数对砂轮组织、强度、耐火度和磨料性能的影响。研究表明通过微波烧结工艺可以达到细化结合剂晶粒，极大缩短烧结时间、降低烧结温度，并在其内部形成稳定的纳米晶须，从而获得强韧化纳米陶瓷结合剂CBN砂轮组织的效果。最后，对经微波烧结过程纳米陶瓷结合剂CBN砂轮进行了磨削性能实验测试，验证了新型砂轮的优越性。