Mechanical and thermal behaviours of grinding acoustic emission

Grinding burn is a common phenomenon of thermal damage that has been one of the main constraints in grinding in respect of high efficiency and quality. Many attempts have tried to utilise Acoustic Emission (AE) technique for identifying grinding burn. However, the AE features of grinding burn are relatively weak and easily merged by other AE sources. This paper presents an investigation of the AE features in terms of grinding mechanical and thermal behaviour. A series tests of single grit scratching, tension testing and laser irradiation were carried out to simulate grinding process in order to separate the mechanical and thermal characteristics of grinding acoustic emission. By means of the Wavelet Packet Transform (WPT), AE features that represent grinding burn temperature can successfully be extracted. These AE footprint features can provide a firm foundation for monitoring and analysing grinding burn.