Transmission Electron Microscopy Characterization of Knoop Indentation Inelastic Deformation Regions in Three Commercial Silicon Carbides
Technical Report,01 Mar 2015,30 Jun 2017
U.S. Army Research Laboratory Adelphi United States
Pagination or Media Count:
Understanding the deformation mechanisms in ceramic materials that govern penetration resistance is crucial for developing better ceramic materials for lightweight body and vehicle armor systems. To determine the mechanistic response of three commercially available armor-grade silicon carbide SiC variants to quasi-static large contact stresses, transmission electron microscopy TEM was used to examine cross sections of the inelastically deformed regions beneath 1-kgf Knoop indents. Due to the potential for extensive cracking around and below the indents, a multistep sample preparation technique was developed to preserve the cross sections intact. TEM specimens were made using the focused-ion beam technique. In general, TEM characterization of the inelastically deformed regions revealed stacking faults, dislocations, transgranular and intergranular microcracking and macrocracking, which varied for each commercial SiC due to variations in their processing and resultant microstructures.
- Inorganic Chemistry
- Test Facilities, Equipment and Methods