Fatigue crack growth study of SCS6/Ti-15-3 composite

Technical Report · Tue Aug 01 04:00:00 EDT 1989

OSTI ID:5419111

Kantzos, P; Telesman, J

A study was performed to determine the fatigue crack growth (FCG) behavior and the associated fatigue damage processes in a (0)(8) and (90)(8) oriented SCS(6)/Ti-15-3 composite. Companion testing (CT) was also done on identically processed Ti-15-3 unreinforced material. The active fatigue crack growth failure processes were very similar for both composite orientations tested. For both orientations, fatigue crack growth was along the fiber direction. It was found that the composite constituent most susceptible to fatigue damage was the interface region and in particular the carbon coating surrounding the fiber. The failure of the interface region lead to crack initiation and also strongly influenced the FCG behavior in this composite. The failure of the interface region was apparently driven by normal stresses perpendicular to the fiber direction. The FCG rates were considerably higher for the (90)(8) oriented CT specimens in comparison to the unreinforced material. This is consistent with the scenario in which the interface has lower fatigue resistance than the matrix, causing lower composite fatigue resistance. The FCG rates of the (0)(8) composite could not be directly compared to the (90)(8) composite but were shown to increase with an increase in the crack length.

• Research Organization: National Aeronautics and Space Administration, Cleveland, OH (USA). Lewis Research Center
• OSTI ID: 5419111
• Report Number(s): N-89-26989; NASA-TM--102332; E--5041; NAS--1.15:102332
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
ALLOYS
CARBIDES
CARBON COMPOUNDS
COMPOSITE MATERIALS
CRACK PROPAGATION
FATIGUE
FRACTURE MECHANICS
MATERIALS
MATRIX MATERIALS
MECHANICAL PROPERTIES
MECHANICS
SILICON CARBIDES
SILICON COMPOUNDS
TITANIUM ALLOYS