Research On Abrasive Wear In Diamond Abrasive Belt Grinding Of Nickel-based Superalloy Blades

Nickel-based superalloy blade is the core component of aero-engine,and its surface quality and machining accuracy directly determine the service performance of aeroengine.Abrasive belt grinding has gradually become an effective precision grinding method for nickel-based superalloy blades.Because the wear rate of common abrasive belt is fast in the grinding process,the consistency of machining accuracy is seriously affected.Diamond abrasive belt has the dual characteristics of "hard" and "soft",and is widely used in the processing of hard and brittle materials such as optical glass and special ceramics.However,there are few researches on the application of diamond in plastic difficult to machine materials,mainly because of the poor thermochemical stability of diamond grains,which leads to the high wear rate.In order to solve this problem,the abrasive wear mechanism and processing performance of diamond abrasive belt under flexible contact state and thermo mechanical coupling are systematically studied.The main research work are as follows:(1)The correlation among process parameters(grinding speed,feed rate,normal pressure,abrasive belt,workpiece material characteristics),state parameters(grinding force,grinding temperature)and diamond belt wear is analyzed.The contact model of complex surface in abrasive belt grinding process is established based on Hertz contact theory.The theoretical model of grinding force and grinding temperature in belt grinding process is established.On this basis,the flexible cutting simulation of single diamond abrasive is carried out to study the influence of grinding speed and cutting depth on grinding force and temperature.(2)In order to study the effect of process parameters on grinding force and grinding temperature,the orthogonal test and single factor test of grinding nickel-based superalloy with diamond abrasive belt were carried out.A neural network prediction model of state parameters with an accuracy of 91.86% is established.At the same time,the effects of process parameters on material removal and surface roughness are studied,so as to provide reference for optimizing grinding process parameters.(3)The wear mechanism of diamond abrasive belt is detected and analyzed,and the neural network prediction model of diamond abrasive belt wear height is established.The prediction accuracy of the model reaches 94.85%.Aiming at compare the processability and wear properties of different types of diamond belts,the comparative tests of electroplated diamond belts and resin diamond belts are carried out.Finally,diamond abrasive belt grinding experiments of typical nickel-based superalloy blades are carried out to analyze the abrasive wear of diamond abrasive belt and the surface quality of blades,and verify the processing performance of diamond abrasive belt.The above research provides technical support for precision abrasive belt grinding of nickel-based superalloy blades.