Methods and apparatus for detecting the presence of cracks in a workpiece by the use of stress waves emitted therefrom

摘要: Microcracks in ceramic substrates are detected by positioning a piezoelectric transducer proximate supporting base for the substrate. The stress waves which emitted cracks form substrate when it is subjected to load converted into electrical pulses transducer. Because brittle material rather than ductile these of low amplitude, short duration, and fast rise time. Special electronic circuitry disclosed detect distinguish them from background noise.