Investigation of the Influence of Structure on Chemical Stability and Thermal/Mechanical Shock Properties of Glass-Like Carbons
Semi-annual technical rept. 2 May-2 Nov 1971
BATTELLE MEMORIAL INST RICHLAND WA PACIFIC NORTHWEST LABS
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This study investigates the chemical reactivity and thermal and mechanical shock behavior of glass-like carbons and correlates these properties with observable structural features. Reactivity studies are selected for initial work. Shock property measurements are incorporated into the program to gain an insight into a potential weakness of glass-like carbon. Work is reported on chemical stability, thermal shock testing, microhardness testing, and surface energy and work of fracture. Sample characterization and microstructural investigations are carried out. Reactivity studies are limited to rate measurements of various carbon forms with oxygen. Rate measurements are conducted on two types of glass-like carbons, an amorphous pyrocarbon, and a standard nuclear graphite. A technique is developed for thermal shocking glass- like carbons using a low power welding arc. Techniques are also developed for measuring mechanical shock using a hardness measuring device. Acoustic emission monitoring has proven valuable in obtaining a real-time indication of crack initiation and propagation. Measurements are made on the shock resistance of three types of glass- like carbons. A quantitative measure of the shock resistance of glass-like carbons is obtained by determining the surface energy and work of fracture. Sample characterization is centered on microscopic examination using both scanning electron and optical microscopy.
- Ceramics, Refractories and Glass