氮化硅陶瓷磨削温度与表面变质层的仿真与实验

为了揭示氮化硅陶瓷磨削温度分布规律以及其对表面成形的影响,首先,建立氮化硅陶瓷纳米级切削的分子动力学模型;其次,研究切削过程中切削参数对切削温度的影响,以及加工过程中切削表面变质层的形成过程;最后,对 K 型热电偶测温和表面能谱分析的仿真与实验结果进行对比分析.结果表明:随着金刚石磨粒切削深度和切削速度的增加,原子晶格发生变形和非晶相变过程中时释放的能量增多,从而使切削温度升高;切削高温会引起氮化硅陶瓷发生非晶相变现象,非晶态原子重新与已加工表面断裂的原子键结合形成表面变质层;分子动力学仿真模型可以用来预测氮化硅陶瓷材料实际磨削加工中磨削温度变化情况,对生产加工具有参考价值.

Simulation and Experiment of Grinding Temperature and Surface Modification Layer of Silicon Nitride Ceramics

In order to reveal the grinding temperature distribution of silicon nitride ceramics and its influence on the surface formation , firstly , the molecular dynamics model for nano-cutting of silicon nitride ceramics was established． Secondly , the influence of cutting parameters on the cutting temperature during the cutting process and the formation process of the cutting surface deterioration layer during the machining process was studied． Finally , the experimental methods of K-type thermocouple measuring temperature and surface energy spectrum analysis were used to compare and analyze the results of simulation research．The results show that as the cutting depth and cutting speed of diamond abrasive grains increase ,the energy released during the deformation of the atomic lattice and the amorphous phase transition increases , and the cutting temperature increases．Cutting high temperature will cause the amorphous phase change phenomenon of silicon nitride ceramics , and the amorphous atoms will recombine with the broken atomic bonds on the processed surface to form the surface metamorphic layer．The molecular dynamics simulation model can be used to predict the change of the grinding temperature in the actual grinding of silicon nitride ceramic materials , which has reference value for production and processing．