Grain wear evolution of cubic boron nitride abrasives during single grain grinding of powder metallurgy superalloy FGH96

Abstract

The grain wear evolution during grinding powder metallurgy superalloy FGH96 using a single abrasive grain of cubic boron nitride (CBN) under different undeformed chip thickness and abrasive wheel speed was investigated. The wear behavior of single abrasive grain (SAG) was extracted based on the variation feature of grinding force, radial wear, grain topography and material remove characteristics. Meanwhile, acoustic emission (AE) testing is used to analyze the grain wear evolution. The results show that micro fracture firstly occurs at the original defects of SAG at the initial wear stage. Attrition wear and micro fracture are responsible for the steady wear stage, while micro and macro fracture are dominant at severe wear stage. Besides, the manner of the plastic adiabatic shear remove occurs in the process of grinding FGH96. Furthermore, sudden increase of root mean square (RMS) of AE signal can be applied to reflect the fracture of SAG, whereas the continuously gradual decrease can be considered the attrition wear or material adhesion, which can provide a technical support for monitoring the grain wear during grinding.