Research On Laser Assisted Grinding Mechanism And Process Of Super-hard Alloy

With the continuous progress of science and technology,the performance of materials plays a decisive role in many industries.Super-hard alloy materials have such excellent characteristics as high strength,high wear resistance,high heat resistance and stable chemical properties under extreme conditions.They are widely used in modern industrial sectors and new technology fields such as aerospace,chemical industry,mechanical electronic components,national defense and so on.Laser heating auxiliary is based on the material surface with high energy laser beam so that the materials surface to absorb energy and then make the surface material to heat up,a small scale through the internal heat transfer function is passed to the work-piece,the work-piece in a short period of time to achieve a certain range of temperature increases,reduce intensity of material,improve the toughness of the material,and make the material hardness and a drop in temperature resistance,improve the processing performance of materials.The main research contents of this thesis are as follows:(1)The mechanism of laser assisted grinding for super-hard alloys is studied.The effect of laser thermal aid on temperature,hardness and toughness of super-hard alloy materials is studied.To investigate the effect of laser thermal assist on grinding force of single grinding particle.(2)The thermal effect of laser on materials is analyzed,and the mathematical thermal model of temperature distribution of super hard alloy YG6X under laser scanning is established and calculated theoretically.The temperature distribution on the surface of super-hard alloy under laser irradiation is simulated.The effects of laser scanning speed,laser power and spot radius on the temperature distribution of work-piece are studied.The correctness of the simulation results is verified by the temperature measurement experiment.(3)The single factor experiment of laser power and scanning speed of laser assisted grinding of super-hard alloy is carried out by the existing laser assisted grinding equipment to find the suitable machining parameters.Orthogonal and contrastive experimental designs and surface roughness results of laser assisted grinding of super-hard alloy YG6X are carried out.By comparing the experimental results of the two processes,the influence of laser thermal assisted machining process parameters on the surface roughness is studied to find the optimal combination of machining parameters.A surface roughness prediction model under laser thermal assistance is established to provide a reference for future processing in this field.(4)Through the simulation analysis of the removal process of a single grinding particle,the residual stress of the surface after laser thermal assisted machining and conventional grinding is obtained,and then the surface hardening after machining is analyzed.The hardness of the surface after grinding with different laser power is measured and the effect of laser thermal assistance on the surface hardening after machining is verified.Laser thermal assisted grinding is carried out by loading different laser power and the grinding wheel wear is studied and analyzed experimentally.