In situ bend fixture for deformation and fracture studies in the environmental scanning electron microscope

Abstract

A computer controlled loading fixture has been designed to allow in situ observation of fracture processes during bending deformation of metal/ceramic microlaminates in an electroscan environmental scanning electron microscope (ESEM). The stage has the capability of accommodating either three- or four-point bending experiments. A unique design feature of the stage is that the specimen surface remains at a fixed distance from the secondary electron detector and, hence, in focus during bending. The sample rests on the fulcrum which remains in a fixed position while the restraints that grip the ends of the sample descend on a ball slide. The system is controlled by a Macintosh IIci computer and National Instruments NB-MIO-16L-9 data acquisition card. National Instruments LabVIEW(R)2 software is used to control the stage displacement and to record the load cell and transducer outputs. The operation of this instrumentation in the ESEM is illustrated by the study of fracture processes in ceramic and ceramic/metal microlaminate films deposited on ductile metallic substrates.

Design and Construction of a Quantitative Uniaxial Straining Stage For The Environmental SEM

“…The environmental scanning electron microscope (or Environmental SEM) is a powerful tool in the materials science laboratory. The large sample chamber and ability to operate in a very poor vacuum (>5Torr) makes it an ideal device for a wide variety of in-situ studies 1 ' 2 ' 3 . A three point bending stage has been used in the ElectroScan E3 environmental SEM at the University of Michigan for over four years.…”