Propagation of indentation fracture was firstly monitored on α-SiC ceramics through a current drop accompanied by the decrease in current conduction area. The current decrease ratio before and after indentation during the constant voltage application was proportional to the crack area formed. However, during the indentation, the current anomalously increased even though the indentation crack propagated. This phenomena is probably due to the piezoresistance effect which has already been reported in SiC single crystal. When bending stress was applied to α-SiC ceramics, the current increase ratio was proportional to the bending strain. A fracture foreseeing system is proposed for α-SiC ceramics in which initial crack monitoring without stress application and bending strain monitoring utilizing the piezoresistance effect are combined.
