Research On Grinding And Polishing Method Of The Elastic Soft-bonded Abrasive Tool

Hard and brittle materials such as sapphire（α-Al₂O₃）,silicon carbide（SiC）,and optical glass are widely used in aerospace,biomedical,optoelectronic information,instrumentation and other high-end fields.In the process of ultra-precision machining of hard and brittle material parts,it is not only necessary to meet the requirements of shape accuracy and surface roughness through micron or nano-level material removal,but also to avoid surface and sub-surface damage to maintain the integrity of the material,which is gradually difficult to meet the compound demand of processing efficiency and processing quality by conventional processing methods.Abrasives based on rubber and other substrate materials have been widely studied at home and abroad because of their ability to achieve nanometer surface roughness while maintaining high material removal efficiency and avoiding surface scratches and damage through adaptive grinding and polishing with elastic contact.In order to further explore the ultra-precision compliant grinding and polishing technology with high efficiency,high precision and low loss,and to explore the mechanism of flexible contact ultra-precision grinding and polishing,this paper proposes a silicone rubber matrix soft-bonded abrasive tool,and conducts an in-depth study on the material removal and surface creation mechanism of its grinding and polishing process,through theoretical analysis,model simulation,experimental validation and other research methods,and carries out the following specific research:1.Research on the machining principle of the elastic abrasive tool.Based on the Hertz contact theory,the contact model between the elastic matrix and the processing object was established.The stress distribution in the contact area was visualized and analyzed.The stress state of soft-bonded abrasive particles in the matrix during the grinding and polishing process was analyzed by theoretical derivation and finite element simulation.The characteristics of high efficiency and low loss of the elastic soft-bonded abrasive tool were verified by experiments.2.Establishment and experimental verification of material removal model for compliant grinding and polishing.Based on the Preston equation and the contact stress distribution and kinematics analysis,an optimal material removal model for compliant grinding and polishing was proposed,which considered the wear mechanism of single abrasive particle and the number of effective abrasive particles.The material removal rate and the material removal profile in the polishing area of the single point dwell grinding and polishing were predicted.The rationality of the model was verified by polishing experiments of quartz glass.3.Surface quality prediction for compliant grinding and polishing of hard and brittle materials.The surface quality prediction model was established based on the trajectory dispersion and trajectory matrix,and the influence of process parameters such as feed rate and trajectory spacing on surface quality was studied.Combined with the control of the position and angle of abrasive tool,the characteristic compliant polishing strategy of curved surface was explored.The accuracy of the surface quality prediction model was verified by the compliant grinding and polishing experiments of silicon carbide and alumina ceramic workpiece.