Study On Small Diameter Deep Hole Of Hard And Brittle Materials By Ultrasonic Vibration Of Rack Cold Roll-beating

With the impact of intellectualization and Internet of Things on traditional and old industries,the increasing improvement of scientific and technological means promotes the development of modern industrial technology towards the trend of intellectualization,high quality,innovation and high efficiency.The emergence of many new materials has brought new possibilities to modern industry.Among them,hard and brittle materials(such as optical glass,silicon crystal,gemstone,ceramics,etc.)are more and more used in aerospace,ship,optics,biomedicine,national defense industry and nuclear industry,and play an extremely important role.Because of the special properties of hard and brittle materials,brittle fracture is easy to occur,and the surface roughness of processed products is difficult to control,which easily affects the performance of its practical application.However,in order to ensure that hard and brittle materials can be adapted to more equipment,the processing of micro-diameter deep holes is indispensable,so how to control the fracture of brittle materials and reduce their surface roughness to the minimum is very important for the practical application of brittle materials.In this thesis,through the theoretical analysis of ultrasonic vibration sleeved optical glass,the motion trajectory of ultrasonic vibration sleeve cutting is obtained,and based on this,the removal mechanism of the material under the processing mode is deeply explored.Through the optical glass indentation experiment,a series of theoretical proofs were made on the formation of cracks,which further verified the influence of various factors on the brittle materials in the processing mode.The optical glass was scratched by ultrasonic vibration diamond indenter,and it was found that the scratched surface with ultrasonic vibration was significantly better than the scratched surface without ultrasonic vibration.In order to study and optimize the surface roughness of the hole wall after drilling,the ultrasonic vibration test platform is built.Combining the existing theoretical experience and equipment parameters.the appropriate combination of test parameters is selected,and it is ptrliminarily concluded that each different parameter combination will be the hole.The surface roughness of the wall caused experimental conclusions with different effects.Through the orthogonal test analysis,the primary and secondary factors affecting the surface roughness of the hole wall arc:spindle speed>amplitude>feed rate.The regression equation of the orthogonal test results is used to obtain the regression equation of the spindle speed(Z1)and the amplitude(Z3)to the surface roughness(vm).In order to verify the conclusion of the experiment of ultrasonic vibration sheathing optical glass,simulation experiments were carried out using Ansys Ls-Dyna software.The equivalent stress of the hole wall produced by the ultrasonic vibration sheathing of optical glass is simulated under different parameters,and the equivalent stress curve is obtained.Through analysis,it is found that when the diameter of the small diameter deep hole is 3 mm,the spindle smpeed is 3000 r/min,the amplitude is 15 micron,and the feed speed is 5 mm/min.The equivalent stress on the hole wall reaches the maximum value.That is to say,the optimal solution of the ultrasonic vibration sheathing optical glass test is obtained when the parameters are combined into three factors.