Monitoring crack advance using acoustic emission and combined acoustic emission and potential drop in Zr-2.5%Nb

Experimental results are reported on the application of acoustic emission (AE) and combined acoustic emission and potential drop (PD) in crack advance measurement. Acoustic emission by itself is not a quantitative technique for measuring crack advance. Compared with the application of only PD, using both simultaneously turns out to be quite beneficial. Used to measure delayed hydride cracking velocity in Zr-2.5%Nb, combined AE and PD, together with other techniques such as fractography, produces more reliable results with higher accuracy for isothermal conditions and particularly during temperature transients. Information about the correlation between AE and PD signals has been also obtained, which improves our understanding of the processes being studied.