Abstract:
On-process quantitative nondestructive evaluation is necessary to promote more advanced extrusion forming of green ceramic. New ultrasonic sensing is proposed both for mechanical characterization and nondestructive inspection of extruded green body. As a prototype transducer array, two-couple transducer system with the fixed frequency of 10 MHz was housed in the forward extrusion former to make on-process measurement both in the normal and the 45°-inclined directions to a cavity channel. The acoustic velocity in the specimen is 776 m/s by off-line measurement; it varied by the change of mechanical properties due to high pressure in forming. The measured ultrasonic signals were found to have sufficient sensitivity and S/N ratio to detect the artificial defects only by comparison of the peak intensity to the full-dense greens. Furthermore, the size and position of pores inside the cavity channel can be predicted even in forming.
(Ref. SXVIII-034-97)
Source: NDE of Ceramics '97 May 4-7, Symposium on Nondestructive Evaluation of Ceramics
at the American Ceramic Society 99th Annual Meeting, Cincinnati, Ohio.
Buying the Symposium Proceedings from the American Ceramic Society.
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