Application of acoustic emission technique in high temperature oxidation studies

Abstract

Acoustic Emission Technique which is capable of detecting the initiation of microracks in the surface oxide films, was utilized in studying the initiation of breakway oxidation and in-situ spalling of the oxide scales formed on metals and alloys at high temperatures. The technique has been successfully applied to detect the breadway oxidation in 2Cr-1Mo and 9Cr-1Mo steels, in-situ scale spalling and anomalous behaviour of copper oxide oxide scale formed at 773 K. Time domain, frequency domain and amplitude distribution modes were used to study these phenomena and AE results have been corroborated with corresponding thermogravimetric results.