A SCANNING ELECTRON-MICROSCOPE BASED MICROINDENTATION SYSTEM

The design and characterization of a scanning electron microscope based microindentor is presented. Dynamic, high magnification imaging of the indentor-specimen contact zone is possible, permitting observation of indent events. Applied load as a function of indentor tip displacement is continuously monitored during indentation. The maximum applied load capability of 20 N is measured to a resolution of 1 mN with a piezoelectric transducer mounted on the indentor shaft. Displacement is measured with a specially developed capacitance gauge that is again mounted on the indentor shaft near the indentor tip and records tip displacement with respect to the specimen surface to a resolution of 10 nm over a 100 mum range. The instrument is vacuum compatible, capable of remote operation, has a short measurement loop, and a potentially high bandwidth response. Results from a fiber push-down test on a SiC fiber reinforced glass ceramic are reported to illustrate the capability of the instrument in performing measurements across the nanoindentation and microindentation ranges.