Design Of Magnetic Source And Process Parameters Optimization Of Magnetic Abrasive Finishing On The Excircle Face Of 18CrNimMo7-6

Gears are the key components of the transmission system.Compared with western developed countries,domestic products generally have problems such as short life,poor carrying capacity and poor quality controllability.In order to meet the development requirements of current and expected high-end equipment for the mechanical manufacturing technology of key core components,improve the service life of gears,and accelerate the transformation of China from a gear manufacturing giant to a gear manufacturing powerhouse,Academician Zhao Zhenye put forward the "anti-fatigue manufacturing technology" which endows members with shape,position and ultimate service performance.And the core content of this technology is "stress-free concentration".Some studies have shown that the stress concentration factor increases with the increase of surface roughness,while the corresponding fatigue life decreases.After carburizing and quenching,18CrNiMo7-6 has excellent mechanical properties,such as high surface hardness and toughness.And it is widely used in heavy-duty parts and parts subjected to cyclic stress,such as gears,etc.Magnetic abrasive finishing is an advanced surface finishing technology.It is used to reduce the surface roughness of 18CrNiMo7-6 parts and study the influence of process parameters on the three-dimensional morphology of the workpiece's outer circular surface,so as to promote the anti-fatigue manufacturing of the product.The main contents of this paper are as follows:(1)Analyses of magnetic field forces on magnetic abrasive grains outside the machining gap and in the machining gap,the force of the magnetic abrasive brush on the surface of the workpiece,the proximity speed of the magnetic abrasive particles flying away from the processing region,and the mechanism of the magnetic particles removing the workpiece material.(2)The design of magnetic abrasive finishing equipment and the detailed introduction of manufacturing process and assembly.And the simulation of electromagnetic sensors by Ansoft Maxwell software.(3)Research on process parameters were conducted for improving the excircle face quality of carburized and quenched steel 18CrNiMo7-6.The mixed orthogonal test table was established by using the method of mixed orthogonal test.The three-dimensional surface roughness value Sa was used as the main inspection index,and the results of mixed orthogonal experiment were analyzed by range analysis and variance analysis.The results obtained from the above research are as follows: Theoretical derivation of the force formula of magnetic particles outside the processing area,Powered by CA6140,a magnetic abrasive equipment for replaceable magnetic pole heads on the outer surface of rotating bending fatigue specimens with Kt=1 was developed;Distribution of coil magnetic potential and flux density on the end face of workpiece is obtained by analysis;The order and optimal combination of the process parameters affecting the three-dimensional excircle face roughness of the carburized and quenched alloy steel 18CrNiMo7-6 by MAF.