Surface Formation Mechanics and its Microstructural Characteristics of AAJP of Aluminum Alloy by Using Amino Thermosetting Plastic Abrasive

Abstract

In this study, a two-dimensional model according to the microcutting mechanism of abrasive particle was developed to demonstrate the mechanics of surface formation of the abrasive air jet polishing (AAJP) of aluminum alloy using amino thermosetting plastic (ATP) abrasive. It is shown that due to the characteristics of medium hardness and angular shape of ATP particle, the impacted surface can be generated by particle sliding, ploughing, microcutting, and indentation with the impinging angle increasing from 0o to 90o. Moreover, the effects of particle impacting on the surface microstructural characteristics, especially residual stress, have been analyzed. It has been found that, compared with particle ploughing and sliding processes, particle microcutting and indentation processes have an obvious effect on the surface residual stress; furthermore, particle microcutting process that can cause the impacted surface with high material deformation and ductility is more beneficial for improving the compressive residual stress than particle indentation process. The results of the study are expected to be applied to improve the fatigue performance of integral and large aircraft structures made of aluminum alloy or other metal materials.