HIGH-TEMPERATURE STRAINING STAGE FOR IN-SITU EXPERIMENTS IN THE HIGH-VOLTAGE ELECTRON-MICROSCOPE

A new double-tilting straining stage for in situ deformation in the high-voltage electron microscope at temperatures above 1000 degrees C has been designed to directly investigate plasticity and fracture of ceramics. The deformation equipment is mounted in a tilted cone of a top entry tilting stage. The load train consists of both a fixed and a moveable lever. The deformation is driven by the thermal extension of a stainless steel rod. The specimen grips are heated by electron bombardment via filaments in a notch of each grip. The heat is led away by water cooling in the levers as well as in the tilted cone. The force acting on the specimen can be measured by a bridge of four semiconducting strain gauges. First experiments have been performed on silicon between 530 degrees C and 780 degrees C and on silicon nitride ceramics and cubic and t'-zirconia single crystals at about 1150 degrees C.