화학공학소재연구정보센터
Journal of Materials Science, Vol.34, No.17, 4233-4237, 1999
Monitoring of indentation fracture and bending strain in alpha-SiC ceramics utilizing electrical response
Propagation of indentation fracture was firstly monitored on alpha-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 reported in SiC single crystal. When bending stress was applied to alpha-SiC ceramics, the current increase ratio was proportional to the bending strain. A fracture foreseeing system is proposed for alpha-SiC ceramics in which initial crack monitoring without stress application and bending strain monitoring utilizing the piezoresistance effect are combined.