Effect of processing on fracture toughness of silicon carbide as determined by Vickers indentations

Technical Report · Mon May 01 04:00:00 EDT 1989

OSTI ID:5676834

Dannels, C M; Dutta, S

Several alpha-SiC materials were processed by hot isostatic pressing (HIPing) and by sintering an alpha-SiC powder containing boron and carbon. Several beta-SiC materials were processed by HIPing a beta-SiC powder with boron and carbon additions. The fracture toughnesses K(sub 1c) of these beta- and alpha-SiC materials were estimated from measurements of Vickers indentations. The three formulas used to estimate K(sub 1c) from the indentation fracture patterns resulted in three ranges of K(sub 1c) estimates. Furthermore, each formula measured the effects of processing differently. All three estimates indicated that fine-grained HIPed alpha-SiC has a higher K(sub 1c) than coarsed-grained sintered alpha-SiC. Hot isostatically pressed beta-SiC, which had an ultrafine grain structure, exhibited a K(sub 1c) comparable to that of HIPed alpha-SiC.

• Research Organization: National Aeronautics and Space Administration, Cleveland, OH (USA). Lewis Research Center
• OSTI ID: 5676834
• Report Number(s): N-89-21895; NASA-TM-101456; E-4565; NAS-1.15:101456
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360203* -- Ceramics
Cermets
& Refractories-- Mechanical Properties
ALLOYS
BORON ADDITIONS
BORON ALLOYS
CARBIDES
CARBON ADDITIONS
CARBON COMPOUNDS
DATA
EXPERIMENTAL DATA
FABRICATION
FRACTURE PROPERTIES
HOT PRESSING
INFORMATION
MATERIALS WORKING
MECHANICAL PROPERTIES
METALLURGY
NUMERICAL DATA
POWDER METALLURGY
PRESSING
SILICON CARBIDES
SILICON COMPOUNDS
STRESS ANALYSIS