Process Control And Experimental Study Of Diamond Wire Saw Cutting Hard And Brittle Materials

Consolidated abrasive diamond wire saw processing technology is widely used in the processing of hard and brittle materials.However,in the process of wire saw cutting,the cutting force on the workpiece will change constantly due to various factors,which directly affects the processing efficiency and the surface quality of the wafer.Therefore,it is necessary to apply some control methods to the cutting process so as to keep the cutting force stable in order to improve the cutting efficiency and wafer surface quality.In this study,the force of the workpiece in wire saw cutting process is analyzed.It is concluded that in the process of wire saw cutting,the workpiece is mainly affected by the normal cutting force and tangential cutting force,and the main processing parameters that affect the cutting force are the feed rate of the workpiece and the wire saw velocity.Based on this,a constant parameter experiment was designed to investigate the influence of single variable(workpiece feed rate or wire saw velocity)on the normal cutting force and tangential cutting force during the cutting process,and the surface morphology,roughness and total thickness variation(TTV)of the wafer after processing were analyzed.In order to realize real-time adjustment of processing parameters(workpiece feed rate or wire saw velocity)in the process of wire saw cutting so as to stabilize the cutting process,a motion control platform for wire saw cutting process was built,and a control algorithm for wire saw cutting process was developed.The incremental PI control model is substituted into the reciprocating wire saw cutting model to establish the closed-loop transfer function model of the diamond wire saw cutting control system.The time constants of the system are obtained by experiment and simulation and the control parameters are substituted into the model.The simulation results show that the control parameters are applied to the wire saw cutting process.The simulation results show that the control effect is good.According to the test results of fixed parameters,the reference cutting force is selected and the control parameters are applied to the reciprocating wire saw cutting system.By comparing the waveforms of normal and tangential cutting forces,the processing time,the surface roughness and surface morphology of the slices after processing,it can be concluded that the cutting force is controlled by the feed rate of the workpiece.Normal and tangential cutting force waveforms are relatively stable,and greatly shorten the processing time and improve the surface quality of the slices after processing.For the linear saw speed as control,the normal and tangential cutting force waveforms are better,but the processing efficiency and surface quality of the slices are not significantly improved.