Fracture mechanisms of the SCS-6 fiber-reinforced titanium alloy matrix composites

Thesis/Dissertation · Mon Dec 31 23:00:00 EST 1990

OSTI ID:7201555

Jeng, Shwangming

Tensile, notched 3-point bending, low-cycle-fatigue and fatigue-crack-propagation tests were conducted at room temperature on the unidirectional SiC fiber-reinforced Ti-15V-3Cr-3Al-3Sn, Ti-6Al-4V and Ti-25Al-10Nb-3V-1Mo composites. Microstructural parameters controlling the deformation, damage initiation, and growth of the composites were investigated using metallographic technique and fractographic analysis. These parameters include interfacial reaction between fiber and matrix, interfacial mechanical properties, matrix toughness, fiber strength and loading conditions. The resulting deformation and fracture mechanisms of these composites under quasi-static and notched 3-point bend loading were classified on the basis of the ratio of the fiber strength ({delta}{sub f}) to interfacial shear strength ({tau}{sub i}) vs. matrix toughness. These failure mechanisms will provide a scientific basis for the development of an analytical model to predict the micro and macro-fracture processes of fiber-reinforced metal-matrix composites. Furthermore, the low-cycle-fatigue damage diagram was constructed using the maximum stress in the fiber vs. fatigue life.

• Research Organization: California Univ., Los Angeles, CA (United States)
• OSTI ID: 7201555
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360602 -- Other Materials-- Structure & Phase Studies
360603* -- Materials-- Properties
ALLOYS
COMPOSITE MATERIALS
CRACK PROPAGATION
CRYSTAL STRUCTURE
FATIGUE
FIBERS
FRACTURE PROPERTIES
MATERIALS
MATRIX MATERIALS
MECHANICAL PROPERTIES
MICROSTRUCTURE
TITANIUM ALLOYS
TITANIUM BASE ALLOYS