Sputter deposition and characterization of MoSi sub 2 /SiC composite coatings

Conference · Tue Dec 31 23:00:00 EST 1991

OSTI ID:7164646

Hirvonen, J-P; Kattelus, H; Suni, I; Likonen, J ^[1]; Jervis, T R; Nastasi, M ^[2]

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1. Technical Research Centre of Finland, Espoo (Finland)
2. Los Alamos National Lab., NM (United States)

We have deposited layered structures of MoSi{sub 2}/SiC composite coatings on different substrates by using a sputtering technique. SiC was used for a constituent of this structure because of the thermodynamic stability of the MoSi{sub 2}/SiC system. DC -magnetron and rf -diode systems were used to sputter MoSi{sub 2} and SiC, respectively. The substrates were mounted on a rotating holder allowing successive deposition Of MoSi{sub 2} and SiC layers. The total number of sublayers of each kind was 90. The thickness of the MoSi{sub 2} sublayers was 10 mn and that of the SiC 3 mn. The coatings were characterized in terms of a composition and microstructure by Rutherford backscattering (RBS), secondary ion mass spectrometry (SIMS),x-ray diffraction, indentation fracture, and nanoindentation. The layered structure was still observed after the coating was annealed at 500{degrees}C for 1 h, which recrystallized the MoSi{sub 2} layer. However, hardness and indentation modulus were increased from 11.6{plus minus}0.8 and 220{plus minus}20 GPa to 20.8{plus minus}1.2 and 290{plus minus}30 GPa, respectively. Preliminary indentation fracture measurements indicate that the layered structure is more brittle than a single, amorphous as-deposited MoSi{sub 2} layer. ,Althoug no improvement in the room teruperature toughness was obtained, the hardness of the recrystallized composite coating was significantly higher than reported previously for a MoSi{sub 2}/SiC composite.

• Research Organization: Los Alamos National Lab., NM (United States)
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 7164646
• Report Number(s): LA-UR-92-2604; CONF-9206271--1; ON: DE92040326
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360601* -- Other Materials-- Preparation & Manufacture
360602 -- Other Materials-- Structure & Phase Studies
360603 -- Materials-- Properties
CARBIDES
CARBON COMPOUNDS
COATINGS
COHERENT SCATTERING
COMPOSITE MATERIALS
CRACKS
CRYSTAL STRUCTURE
DEPOSITION
DIFFRACTION
FRACTURE PROPERTIES
HARDNESS
LAYERS
MATERIALS
MECHANICAL PROPERTIES
MICROSTRUCTURE
MOLYBDENUM COMPOUNDS
MOLYBDENUM SILICIDES
RECRYSTALLIZATION
REFRACTORY METAL COMPOUNDS
SCATTERING
SILICIDES
SILICON CARBIDES
SILICON COMPOUNDS
SPUTTERING
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION