Acoustic emission studies of cermet BK structural modifications under thermal and radiation action and hydrogenation

Elastic wave attenuation and acoustic emission (AE) in tungsten monocarbide base cermets were investigated with the purpose of studying structural changes and microplastic strains under heating within the range of 100-1000 K, gamma-irradiation up to absorbed dose of 107 J×kg-1 and hydrogenation. Interrelations were revealed of AE signals and a decrement of elastic wave damping to temperature- and radiation-induced transformations in microstructure of 94% WC-6% Co and 92% WC-8% Co hard alloys. AE peaks under thermal action were found to be associated with cobalt phase microstrain or with dislocation rearrangement due to thermal diffusion of hydrogen in preliminary hydrogenated alloys.