Research On The Wear Mechanism And Theoretical Model Of Ceramic Tool-Part Coupling Tool In Turning Engineering

To monitor and predict tool wear is of great importance to production and processing,which exerts direct influence on cutting force,cutting temperature,and roughness and precision of machined surface.The present researches both at home and abroad are mainly focused on the cutting and processing of plastic metal materials,with few attentions paid to the tool wear mechanism and modeling of hard and brittle materials such as engineering ceramics during the cutting and processing.However,engineering ceramics,which excel in chemical stability,play an indispensable role in such fields as high precision equipment,medical devices,large-scale aviation and navigation and in particular,has become a kind of popular hot processing material in recent years.Therefore it is of great necessity and realistic significance to study tool wear mechanism and modeling of engineering cutting and processing.The tool wear theoretical model of engineering ceramics was established in this paper through studying the process of removing engineering ceramics brittle materials and tool wear mechanism.The selection of tool angle and material property were also discussed in this paper:(1)The essence of the material migration of tool wear was described more appropriately and the relation between the strength of cutting tools and wear was tested more scientifically by introducing tool wear volume after transforming the flank wear width to tool wear volume in the traditional cutter wear prediction,upgrading from local to overall layout and from 2D to 3D.To address the difficulty in calculating the tool wear volume,the non-wear volume of the tool nose was calculated using the idea of layer cubing and the method of calculus.(2)Based on tribology,geometry and kinematics,the tool wear mechanism of brittle materials during the dry cutting process was put forward in this paper,where the way of abrasive wear between the tool wear surface and the workpiece surface was also analyzed.On the basis of considering the wear forms of cutting tools made of different materials,a wear theoretical model of brittle material turning tool was built systematically and was further verified through several experiments on engineering ceramics of turning tools.The wear mechanism of engineering ceramics was studied,the removal mechanism of abrasive particles and the furrow effect of grain on cutting tools were analyzed.Through measuring the actual machined surface area and observing the micro abrasive particles by the super DOF microscope,the work form of abrasive particles on the wear surface of cutting tools was analyzed.The furrow effect and three-body abrasion were explained from a micro level.(3)As for the weakness of too small scope of application of the mechanism model,the microscopic wear of several common types of turning tools was compared and analyzed.In consideration of the mutual interference between hard particles and ceramic abrasive particles contained in the tool wear,the effect of adhesive wear was taken into account,in addition to the abrasive wear.The adhesive wear coefficient and hard particle interference coefficient were calculated through the cutting experiment and wear mechanism to enlarge the applicability of the tool wear model.