High Frequency Ultrasonic Evaluation of Ceramics for Gas Turbines

[+] Author and Article Information
T. Derkacs, I. M. Matay, W. D. Brentnall

TRW INC., Cleveland, Ohio

J. Eng. Power 100(4), 549-552 (Oct 01, 1978) (4 pages) doi:10.1115/1.3446392 History: Received December 07, 1978; Online July 14, 2010


To assure reliable performance of ceramic materials in gas turbine engines, where performance at 1400°C for up to 10,000 hrs is required, it is necessary to screen out material with defects in the size range of 10 to 100 μm. Investigation of high frequency ultrasonic inspection techniques has led to development of longitudinal, shear, and surface wave methods capable of detecting defects at least down to 25 μm in size. The approach is to use a focused 45 MHz ultrasonic transducer in a pulse-echo immersion mode of operation. Inspections were performed on hot pressed silicon nitride containing natural defects, seeded inclusions and artifical surface cracks. The discussion includes a description of the inspection techniques and a presentation of the results of ultrasonic inspections, four-point-bend testing and scanning electron microscopy of defect containing specimens.

Copyright © 1978 by ASME
Your Session has timed out. Please sign back in to continue.





Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In