Tensile-strength characterization of a metal-matrix composite with circular holes. Master's thesis

Technical Report · Sun Dec 01 04:00:00 EST 1991

OSTI ID:5832138

Rattray, J

Static tensile testing conducted at room temperature and 650 C shows notch sensitivity for a quasi-isotropic lay-up of a titanium alloy metal matrix composite. The specific material used was SCS-6/Beta 21S. Some unnotched specimens were tested and then the diameter-to-width ratio was varied from 0.1 to 0.4. The room temperature unnotched strength is 840 MPa, and the strength falls to less than half this value at 650 C. The off-axis plies of the (0, + or - 45, 90)s lay-up exhibit debonding of the fibers from the matrix at only ten percent of failure stress. This debonding is shown with acetate replicas and acoustic emission. By modeling the debonded plies with the Halpin-Tsai equations, a modulus is calculated for the debonded material which correlates very well with the experimental modulus. A fiber dominated failure exists at both temperatures, but the fiber pullout exists only at 650 C. Etching away the matrix from the 0 fibers showed a small area near the hole where fibers were damaged. The size of this damage zone correlated very well with the critical distance for the Whitney-Nuismer Point Stress failure prediction method.

• Research Organization: Air Force Inst. of Tech., Wright-Patterson AFB, OH (United States). School of Engineering
• OSTI ID: 5832138
• Report Number(s): AD-A-243894/3/XAB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
ACETATES
ALLOYS
AMBIENT TEMPERATURE
CARBIDES
CARBON COMPOUNDS
CARBOXYLIC ACID SALTS
COMPOSITE MATERIALS
DAMAGE
ETCHING
FABRICATION
FIBERS
MATERIALS
MATERIALS TESTING
MECHANICAL PROPERTIES
NOTCHES
PETROCHEMICALS
PETROLEUM PRODUCTS
PLASTICS
REINFORCED MATERIALS
REINFORCED PLASTICS
REPLICAS
SILICON CARBIDES
SILICON COMPOUNDS
STRESSES
SURFACE FINISHING
SYNTHETIC MATERIALS
TEMPERATURE RANGE
TEMPERATURE RANGE 0400-1000 K
TENSILE PROPERTIES
TESTING
TITANIUM ALLOYS