Characterization of structure and mechanical properties of MoSi{sub 2}-SiC nanolayer composites
Abstract
A systematic study of structure-mechanical properties relation is reported for MoSi{sub 2}-SiC nanolayer composites. Alternating layers of MoSi{sub 2} and SiC were synthesized by DC magnetron and rf-diode sputtering, respectively. Cross-sectional transmission electron microscopy was used to examine three distinct reactions in the specimens when exposed to different annealing conditions: Crystallization and phase transformation of MoSi{sub 2}, crystallization of SiC, and spheroidization of the layer structures. Nanoindentation was employed to characterize the mechanical response as a function of structural changes. As-sputtered material exhibits amorphous structures in both types of layers and has a hardness of 11 GPa and a modulus of 217GPa. Subsequent heat treatment induces crystallization of MoSi{sub 2} to form the C40 structure at 500C and SiC to form the a structure at 700C. The crystallization process is directly responsible for hardness and modulus increase in multilayers. A hardness of 24GPa and a modulus of 340GPa can be achieved through crystallizing both MoSi{sub 2} and SiC layers. Annealing at 900C for 2h causes the transformation of MoSi{sub 2} into the C11{sub b} structure, as well as spheroidization of the layering to form a nanocrystaulline equiaxed microstructure. A slight degradation in hardness but not in modulus is observed accompanyingmore »
- Authors:
-
- Los Alamos National Lab., NM (United States)
- Technical Research Centre of Finland, Espoo (Finland)
- Publication Date:
- Research Org.:
- Los Alamos National Lab., NM (United States)
- Sponsoring Org.:
- USDOE, Washington, DC (United States)
- OSTI Identifier:
- 10112648
- Report Number(s):
- LA-UR-93-4274; CONF-931108-33
ON: DE94004982
- DOE Contract Number:
- W-7405-ENG-36
- Resource Type:
- Conference
- Resource Relation:
- Conference: Fall meeting of the Materials Research Society (MRS),Boston, MA (United States),29 Nov - 3 Dec 1993; Other Information: PBD: [1993]
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 36 MATERIALS SCIENCE; MOLYBDENUM SILICIDES; COMPOSITE MATERIALS; SILICON CARBIDES; LAYERS; MECHANICAL PROPERTIES; CORRELATIONS; SPUTTERING; CRYSTALLIZATION; HEAT TREATMENTS; MICROSTRUCTURE; 360603; 360602; STRUCTURE AND PHASE STUDIES
Citation Formats
Kung, H, Jervis, T R, Nastasi, M, Mitchell, T E, and Hirvonen, J P. Characterization of structure and mechanical properties of MoSi{sub 2}-SiC nanolayer composites. United States: N. p., 1993.
Web.
Kung, H, Jervis, T R, Nastasi, M, Mitchell, T E, & Hirvonen, J P. Characterization of structure and mechanical properties of MoSi{sub 2}-SiC nanolayer composites. United States.
Kung, H, Jervis, T R, Nastasi, M, Mitchell, T E, and Hirvonen, J P. 1993.
"Characterization of structure and mechanical properties of MoSi{sub 2}-SiC nanolayer composites". United States. https://www.osti.gov/servlets/purl/10112648.
@article{osti_10112648,
title = {Characterization of structure and mechanical properties of MoSi{sub 2}-SiC nanolayer composites},
author = {Kung, H and Jervis, T R and Nastasi, M and Mitchell, T E and Hirvonen, J P},
abstractNote = {A systematic study of structure-mechanical properties relation is reported for MoSi{sub 2}-SiC nanolayer composites. Alternating layers of MoSi{sub 2} and SiC were synthesized by DC magnetron and rf-diode sputtering, respectively. Cross-sectional transmission electron microscopy was used to examine three distinct reactions in the specimens when exposed to different annealing conditions: Crystallization and phase transformation of MoSi{sub 2}, crystallization of SiC, and spheroidization of the layer structures. Nanoindentation was employed to characterize the mechanical response as a function of structural changes. As-sputtered material exhibits amorphous structures in both types of layers and has a hardness of 11 GPa and a modulus of 217GPa. Subsequent heat treatment induces crystallization of MoSi{sub 2} to form the C40 structure at 500C and SiC to form the a structure at 700C. The crystallization process is directly responsible for hardness and modulus increase in multilayers. A hardness of 24GPa and a modulus of 340GPa can be achieved through crystallizing both MoSi{sub 2} and SiC layers. Annealing at 900C for 2h causes the transformation of MoSi{sub 2} into the C11{sub b} structure, as well as spheroidization of the layering to form a nanocrystaulline equiaxed microstructure. A slight degradation in hardness but not in modulus is observed accompanying the layer break-down.},
doi = {},
url = {https://www.osti.gov/biblio/10112648},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Fri Dec 31 00:00:00 EST 1993},
month = {Fri Dec 31 00:00:00 EST 1993}
}