Dispersed-metal-toughened alumina

Technical Report · Fri Feb 01 04:00:00 EST 1985

OSTI ID:5896738

Tiegs, T N; Moorhead, A J

Hot-pressed alumina with a fine dispersion of Cr metal particles showed good fracture toughness (K/sub Ic/ less than or equal to 8 MPa.m/sup 1/2/) and thermal shock resistance. However, the fracture strengths of these materials were relatively low (190 to 240 MPa vs 350 to 580 MPa for pure alumina). The good fracture toughness and thermal shock resistance were found to be related to the relatively large-grain duplex microstructure of the hot-pressed materials. The fracture toughness of alumina with dispersions of Ni and Pt was found to be inferior to that of the Al/sub 2/O/sub 3/-Cr materials. Hot-pressed solid solutions of Al/sub 2/O/sub 3/-Cr/sub 2/O/sub 3/ also showed good fracture toughness (K/sub Ic/ = 7.3 to 7.7 MPa.m/sup 1/2/), which was again due to the development of a relatively large-grain duplex microstructure. Implications of these results for dispersion-metal hardening of zirconia are discussed.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5896738
• Report Number(s): DOE/NASA-2801-1; NASA-CR-174687; ORNL/TM-9518; ON: DE85008145
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360200* -- Ceramics
Cermets
& Refractories
ALLOYS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CHALCOGENIDES
CHROMIUM ALLOYS
CRYSTAL STRUCTURE
DISPERSION HARDENING
ELEMENTS
FABRICATION
FLEXURAL STRENGTH
FRACTURE PROPERTIES
HARDENING
MECHANICAL PROPERTIES
METALS
MICROSTRUCTURE
NICKEL
OXIDES
OXYGEN COMPOUNDS
PALLADIUM
PHYSICAL PROPERTIES
PLATINUM METALS
THERMAL CONDUCTIVITY
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES