Evolution Mechanism Of Wear Behavior Of Diamond Abrasives In Rotary Ultrasonic Grinding

With the rapid development of modern aerospace technology,the material performance requirements are becoming higher and higher.As a new aerospace material,hot-pressed Si₃N₄ceramics have excellent wear resistance,chemical stability,low density and high mechanical properties at high temperature.However,as a typical hard and brittle material,hot pressing Si₃N₄ceramics is very difficult to process.Rotary ultrasonic grinding is a kind of processing technology combining ultrasonic high frequency vibration and rotary grinding.Rotary ultrasonic grinding has the advantages of low grinding force and high surface quality.In the process of machining,abrasive wear not only affects the surface quality of ceramic machining,but also has a great influence on the service life of abrasive.In order to improve machined surface quality,reduce abrasive wear and reduce machining cost,it is of great significance to study the evolution mechanism of abrasive wear behavior of diamond abrasives based on rotary ultrasonic grinding.Firstly,according to the ultrasonic vibration characteristics of diamond abrasives in ultrasonic grinding process of hot-pressed Si₃N₄ceramics,the stress analysis of single diamond abrasives was carried out,and the characteristics of different bond agents were analyzed.The inlay mechanism between abrasive grain and binder was analyzed theoretically,and the wear forms and wear stages of diamond abrasives in ultrasonic grinding were determined.Secondly,a 3d stochastic model of diamond abrasive particles is established.Combined with the random properties of diamond abrasive particle morphology,according to the virtual lattice method,and according to the random morphology of the abrasive tool to generate a three-dimensional random model,finally according to the test results,according to the proportion of the wear form to establish a three-dimensional model of the abrasive wear surface topography,to achieve the three-dimensional modeling of the random morphology of the abrasive tool wear.Finally,the rotary ultrasonic grinding experiment was carried out.According to the abrasive wear data obtained after the test,the influence of diamond abrasive on the abrasive wear under different process parameters and tool parameters was analyzed.According to the test results,the influence law of diamond tool wear is analyzed.Abrasive wear experiment and abrasive grinding force test,observation of abrasive wear form,judgment of abrasive wear stage,and the use of scanning electron microscopy（SEM）observation abrasive wear surface morphology and ceramic surface morphology,through the spectrum analysis to explore the causes of the wear abrasive damage,analysis of the law of the different stages of wear surface machining quality.