Metals and Ceramics Division, Oak Ridge National Laboratory, Oak Ridge, TN
Washington State University, Pullman, WA
(Received 17 August 1992; accepted 19 February 1993)
Design and development of a simple mechanical strain extensometer for high-temperature tensile testing of ceramic materials are described. The extensometer uses the lever-arm concept to proportionally reproduce the displacements of fiducial gage marks defined on a specimen. Various potential errors in strain measurement associated with the kinematics of this mechanical extensometer are analyzed and estimated. The extensometer exhibits a resolution of 5 microstrain (μɛ) and good long-term stability under moderate changes of ambient temperature. Limited results of simple isothermal creep tests on silicon nitride tensile specimens are presented to demonstrate the effectiveness of the device.
Paper ID: JTE11785J