Studies on indentation fracture toughness on ceramic and ceramic composite using acoustic emission technique

摘要

This paper is aimed at investigating the acousticemission activities during indentation toughness tests on analumina based wear resistant ceramic and 25wt% silicon carbidewhisker (SiCw) reinforced alumina composite. It has been shownthat the emitted acoustic emission signals characterize the crackgrowth during loading and unloading cycles in an indention test.The acoustic emission results indicate that in the case of thecomposite the amount of crack growth during unloading is higherthan that of loading, while the reverse is true in case of the wearresistant ceramics. Acoustic emission activity observed in wearresistant ceramic is less than that in the case of composite. Anattempt has been made to correlate the acoustic emission signalswith crack growth during indentation test.