Ductile phase toughening of molybdenum disilicide by low pressure plasma spraying

Conference · Wed Jan 01 04:00:00 EST 1992

DOI:https://doi.org/10.1016/0921-5093(92)90317-T· OSTI ID:7030656

Castro, R G; Rollett, A D; Stanek, P W ^[1]; Smith, R W ^[2]

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1. Los Alamos National Lab., NM (United States)
2. Drexel Univ., Philadelphia, PA (United States). Dept. of Materials Engineering

The low fracture toughness of MoSi{sub 2} at ambient temperature has prompted investigations into new processing methods in order to impart some degree of fracture toughness into this inherently brittle material. In the following investigation, low pressure plasma spraying was employed as a fabricating technique to produce spray-formed deposits of MoSi{sub 2} and ductile reinforced MoSi{sub 2} composites containing approximately 10 and 20 volume percent of a discontinuous tantalum lamelli reinforcement. Fracture toughness (K{sub 1C}) measurements of MoSi{sub 2} and the MoSi{sub 2}/Ta composites were done using a chevron notched 4-point bend fracture toughness test in both the as-sprayed condition and after hot isostatic pressing at 1200{degrees}C/206 MPa for 1 hour. Results from the ductile reinforced MoSi{sub 2}/Ta composites have shown fracture toughness increases on the order of 200% over the as-sprayed MoSi{sub 2}. In addition, a marked anisotropy in fracture toughness was observed in the spray-formed deposits due to the layered splat structure produced by the low pressure plasma spray process.

• 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: 7030656
• Report Number(s): LA-UR-92-313; CONF-921184--1; ON: DE92007409
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
360203 -- Ceramics
Cermets
& Refractories-- Mechanical Properties
CRACKS
CRYSTAL STRUCTURE
DEPOSITION
DUCTILITY
FRACTURE PROPERTIES
HARDNESS
MECHANICAL PROPERTIES
MICROSTRUCTURE
MOLYBDENUM COMPOUNDS
MOLYBDENUM SILICIDES
PARTICLE SIZE
PLASMA ARC SPRAYING
REFRACTORY METAL COMPOUNDS
SILICIDES
SILICON COMPOUNDS
SIZE
SPRAY COATING
SURFACE COATING
TENSILE PROPERTIES
TRANSITION ELEMENT COMPOUNDS