Research On Rough Grinding Process Of Natural Diamond Sawing Surface

The common precision cutting methods of natural diamond include laser cutting,water jet guided laser cutting and sawing.The high temperature of laser cutting process will cause ablation,cracks and fracture on the cutting surface of natural diamond,and some diamond will be melted off,resulting in waste of raw materials.In the process of water jet guided laser cutting,the laser energy will be insufficient due to the water jet effect,which will cause more damage to the natural diamond cutting surface and make the subsequent grinding and polishing process more difficult.The cutting of natural diamond by sawing method has less cutting loss,good cutting surface quality and higher economy.However,improper operation in the sawing process will cause knife pattern on the cutting surface and reduce the quality of the cutting surface,so it is necessary to remove the surface damage and improve the surface quality of diamond by rough grinding and then precision grinding and polishing.In addition,in the process of rough grinding,workers blindly increase the load to pursue the processing efficiency without scientific process guidance and cause diamond breakage,which increases the scrap rate.Therefore,it is of great significance to study the rough grinding process of natural diamond sawing surface.Firstly,the grinding principle and testing method of diamond were studied to provide theoretical guidance for the subsequent rough grinding experiments and surface quality inspection.Secondly,the structure of the diamond rough grinding clamping device was designed based on oscillating grinding.The pressure sensor was used to monitor the pressure during the rough grinding process,and the acoustic emission device was used to monitor the acoustic emission signal generated during the rough grinding process,which solved the problem that the traditional rough grinding process cannot realize the quantitative monitoring of the rough grinding parameters.Again,the geometric kinematic model of a single grain relative to the rough grinding diamond was established based on geometric kinematics,and the equations of the trajectory of a single grain relative to the diamond were derived.Matlab software is used to simulate the trajectory of the abrasive grains on the rough grinding surface of the diamond,and the method of evaluating the trajectory of the abrasive grains is elaborated.The influence of grinding disc speed,oscillation angle and oscillation angular velocity on the uniformity of the grinding grain trajectory was studied to provide guidance on the process parameters for the subsequent rough grinding experiments.Finally,the rough grinding experiments on the natural diamond sawn surface were carried out,and the experimental results were examined and analyzed to study the influence of the rough grinding process parameters on the pressure fluctuation,acoustic emission signal,rough grinding efficiency,surface roughness and surface phase during the rough grinding process.Orthogonal experiments were conducted to find the optimal process combination with the roughness of the rough grinding surface as the experimental index.The optimal process combination was used to rough the natural diamond sawn surface.The roughness of the roughly ground diamond surface is found to be smooth and undamaged,and the roughness value decreases from 89.33 nm to 21.20 nm,and the quality fraction of natural diamond increases from 89.6% to 99.3%,which laids the foundation for obtaining a high-quality surface by diamond precision grinding and polishing.