skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: 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 » the layer break-down.« less

Authors:
; ; ;  [1];  [2]
  1. Los Alamos National Lab., NM (United States)
  2. 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}
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share: