Acoustic Emission and Deformation Mode in Ceramics During Indentation

Abstract

Acoustic emission (AE) monitoring was carried out during indentation tests of ceramic materials to reveal different types of emission and to correlate them with microscopic observation in order to identify plastic deformation or cracking phenomena. The results show good correlation between the AE characteristics and deformation mode of ceramics below the diamond indenter. The AE generated by surface cracks are of higher amplitude, longer duration and higher frequency, compared with the phenomenon during plastic deformation. Consequently, deformation processes of ceramics are distinguished by AE signal analysis. Moreover, this monitoring method is effective in examining the threshold load for cracking.