Effect Of Mesocarbon Microbeads On Electrolytic In-process Dressing Grinding Performance Of Multi-layer Brazed Wheel

In order to improve the problems of insufficient film thickness,low film formation efficiency and poor quality of multi-layer brazed diamond grinding wheels in electrolytic inprocess dressing grinding,mesocarbon microbeads(MCMB)are added to the metal bond of the grinding wheel.The influence of the content of MCMB on the mechanical properties and microstructure of the abrasive layer was studied,and the influence of its content on the electrolytic film formation performance of the multi-layer brazed diamond grinding wheel was investigated.The content of MCMB was optimized,and further analyzed the effect of MCMB on the performance of multi-layer brazed grinding wheel electrolytic in-process dressing grinding of ultra-fine grained cemented carbides.The main work and conclusions are as follows:(1)Through the in-depth analysis of the electrochemical process on the anode grinding wheel during the electrolysis process,it provides a theoretical basis for proposing ways to improve the electrolytic film quality of the grinding wheel,and determines the overall experimental plan.The abrasive layer samples of multi-layer brazed diamond grinding wheel with different content of MCMB were prepared by cold pressing and high temperature sintering.(2)The effect of MCMB content on the mechanical properties of sintered body was studied.The research shows that the hardness of the abrasive layer decreases with the content of MCMB.The flexural strength first increases and then decreases,with a maximum of 456.75 MPa and a minimum of 82.63 MPa.The second strengthening effect of MCMB in the matrix is the reason for the change of flexural strength.Excessive content of MCMB will affect the interconnection between the molten powders during the sintering process and adversely affect the properties of the grinding wheel.(3)Through the electrolytic experiments,the effect of MCMB content on the electrolytic film-forming properties of the multi-layer brazed grinding wheel was analyzed.The experiment found that the electrolytic equilibrium current gradually stabilized with the increase of MCMB content,and the film thickness first increased and then decreased.MCMB can effectively improve the compactness and adhesion strength of the oxide film,and make the resulting oxide film structure uniform,the maximum oxide film thickness is 104μm.The oxide film forming performance of grinding wheel with 6vol.%MCMB is the best.(4)Electrolytic in-process dressing grinding experiments were carried out on ultrafine grained cemented carbides using a multi-layer brazed grinding wheel containing 6vol.%MCMB and a grinding wheel without MCMB.The experiment found that the MCMB can effectively promote the blunt abrasive particles to fall off;the oxide film with enough thickness and good compactness can also effectively play the role of vibration reduction and grinding,improve the grinding quality and reduce the grinding subsurface damage.