Abstract:

The crack-growth-resistance behavior or R-curve behavior of Al₂O₃/SiC_w ceramic cuttingtool material was obtAlNed by employing the Vickers indentation/fracture stress technique. The

R- curve exhibits a steeply rising part while the crack extension is at its initial stage and thefracture toughness increases gently with tile crack propagating further. The quantitative analysisof toughening mechanisms indicates that whisker bridging is the mAlN cause of ascending fracturetoughness at the initial stage of crack extension less than λ, however, whisker pull-out operates significantly in toughening behavior with the increase of crack extension. Additionally, crack deflection also contributes to the increase of fracture toughness.

Key words: R-curve, whisker toughened ceramics, silicon carbide whisker, vickers indentationcrack