Tensile creep behavior of polycrystalline alumina fibers

Technical Report · Thu Jul 01 04:00:00 EDT 1993

OSTI ID:6254588

Yun, H M; Goldsby, J C

Tensile creep studies were conducted on polycrystalline Nextel 610 and Fiber FP alumina fibers with grain sizes of 100 and 300 nm, respectively. Test conditions were temperatures from 800 to 1050 C and stresses from 60 to 1000 MPa. For both fibers, only a small primary creep portion occurred followed by steady-state creep. The stress exponents for steady-state creep of Nextel 610 and Fiber FP were found to be about 3 and 1, respectively. At lower temperatures, below 1000 C, the finer grained Nextel 610 had a much higher 0.2 percent creep strength for 100 hr than the Fiber FP; while at higher temperatures, Nextel 610 had a comparable creep strength to the Fiber FP. The stress and grain size dependencies suggest Nextel 610 and Fiber FP creep rates are due to grain boundary sliding controlled by interface reaction and Nabarro-Herring mechanisms, respectively.

• Research Organization: National Aeronautics and Space Administration, Cleveland, OH (United States). Lewis Research Center
• OSTI ID: 6254588
• Report Number(s): N-93-30938; NASA-TM--106269; E--7995; NAS--1.15:106269; CNN: RTOP 537-04-21
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360203* -- Ceramics
Cermets
& Refractories-- Mechanical Properties
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CHALCOGENIDES
CREEP
CRYSTALS
FIBERS
GRAIN BOUNDARIES
GRAIN SIZE
MECHANICAL PROPERTIES
MICROSTRUCTURE
OXIDES
OXYGEN COMPOUNDS
POLYCRYSTALS
PRESSURE DEPENDENCE
SIZE
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE
TEMPERATURE RANGE 1000-4000 K
TENSILE PROPERTIES