Processing temperature effects on molybdenum disilicide

Journal Article · Sun Nov 01 04:00:00 EST 1992 · Journal of the American Ceramic Society; (United States)

DOI:https://doi.org/10.1111/j.1151-2916.1992.tb04406.x· OSTI ID:6858907

Wade, R K ^[1]; Petrovic, J J ^[2]

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1. Arizona Materials Lab., Dept. of Materials Science and Engineering, Univ. of Arizona, Tucson, AZ (United States)
2. Los Alamos National Lab., NM (United States). Materials Science and Technology Div.

This paper reports on a series of MoSi[sub 2] compacts that were fabricated at increasing hot-pressing temperatures to achieve different grain sizes. The materials were evaluated by Vickers indentation fracture to determine room-temperature fracture toughness, hardness, and fracture mode. From 1500[degrees] to 1800[degrees] C, MoSi[sub 2] had a constant 67% transgranular fracture and linearly increasing rain size from 14 to 21 [mu]m. Above 1800[degrees]C, the fracture percentage increased rapidly to 97% transgranular at 1920[degrees]C (32 [mu] grain size). Fracture toughness and hardness decreased slightly with increasing temperature. MoSi[sub 2] processed at 1600[degrees]C had the highest fracture toughness and hardness values of 3.6 MPa[center dot]m[sup 1/2] and 9.9 GPa, respectively. The effects of SiO[sub 2] formation from oxygen impurities in the MoSi[sub 2] starting powders and MoSi[sub 2]-Mo[sub 5]Si[sub 3] eutectic liquid formation were studied.

• OSTI ID: 6858907
• Journal Information: Journal of the American Ceramic Society; (United States), Journal Name: Journal of the American Ceramic Society; (United States) Vol. 75:11; ISSN 0002-7820; ISSN JACTAW
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
360202 -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
360203 -- Ceramics
Cermets
& Refractories-- Mechanical Properties
360204 -- Ceramics
Cermets
& Refractories-- Physical Properties
CHALCOGENIDES
COMPACTS
CONTROL
CRYSTAL STRUCTURE
ELEMENTS
EUTECTICS
FABRICATION
FRACTURE PROPERTIES
GRAIN SIZE
HOT PRESSING
IMPURITIES
MATERIALS WORKING
MECHANICAL PROPERTIES
MICROSTRUCTURE
MOLYBDENUM COMPOUNDS
MOLYBDENUM SILICIDES
NONMETALS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
PRESSING
PROCESS CONTROL
REFRACTORY METAL COMPOUNDS
SILICIDES
SILICON COMPOUNDS
SILICON OXIDES
SIZE
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE
TEMPERATURE RANGE 1000-4000 K
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
VICKERS HARDNESS