Damage accumulation in advanced metal-matrix composites under thermal cycling. Final report, 1 Oct 87-15 Oct 90

Technical Report · Mon Feb 25 04:00:00 EST 1991

OSTI ID:5360763

Taya, M; Ramulu, M; Armstrong, W; Dunn, M

This research investigates the response to thermal cycling of a set of W-1%THO2 reinforced Fe-25CR-8Al-50Y superalloy matrix composites. During this research, unique composite materials were produced by powder metallurgical processing. These materials were three aligned composites of differing reinforcement aspect ratio, and a hierarchic composite which included fine diameter Al2O3 fibers. After hot isostatic pressing processing, specimen blanks were cut from the HIP billets by abrasive water jets after which specimens were turned using a conventional engine lathe. The specimens were then thermal sprayed with an oxidation resistant FeCrAlY coating identical to the matrix material. The specimens were then thermal cycled between 1100 C and 352 c and between 1100 C and 534 C for 100,500, or 750 cycles on a specially built thermal cycling machine. The dimensional change of each specimen was measured. It was found that the initial longitudinal growth per thermal cycle was small. After many thermal cycles however the longitudinal growth per thermal cycle became much larger. A severe growth of fiber-matrix interfacial damage was documented with scanning electron microscopy. The growth of two interfacial reaction phases was determined with a KEVEX dispersive x-ray analysis. The mechanical properties of the interfacial material were investigated with a Vickers microhardness test. Finally, the basic mechanical response of the material was investigated with room temperature tensile testing.

• Research Organization: Washington Univ., Seattle, WA (United States). Dept. of Mechanical Engineering
• OSTI ID: 5360763
• Report Number(s): AD-A-235002/3/XAB; CNN: AFOSR-89-0059
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
ABRASIVES
ACTINIDE COMPOUNDS
ALLOYS
ALUMINIUM ALLOYS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
ASPECT RATIO
CHALCOGENIDES
CHEMICAL REACTIONS
CHROMIUM ALLOYS
COATINGS
COMPOSITE MATERIALS
CORROSION PROTECTION
CRYSTAL STRUCTURE
DAMAGE
DISPERSIONS
ELECTRON MICROSCOPY
ELEMENTS
ENGINES
FABRICATION
FIBERS
HARDNESS
HEATING
HOT PRESSING
INTERFACES
IRON ALLOYS
LATHES
MACHINE TOOLS
MATERIALS
MATERIALS WORKING
MATRIX MATERIALS
MECHANICAL PROPERTIES
METALLURGY
METALS
MICROHARDNESS
MICROSCOPY
MICROSTRUCTURE
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POWDER METALLURGY
PRESSING
PROCESSING
PROTECTIVE COATINGS
REINFORCED MATERIALS
RESEARCH PROGRAMS
SCANNING ELECTRON MICROSCOPY
THERMAL CYCLING
THERMODYNAMIC PROPERTIES
THORIUM COMPOUNDS
THORIUM OXIDES
TOOLS
TRANSITION ELEMENTS
TUNGSTEN
YTTRIUM ALLOYS