Micromechanisms of fatigue crack growth and fracture toughness in metal-matrix composites. Final technical report, 1 August 1988-28 April 1990

Technical Report · Thu Jun 28 04:00:00 EDT 1990

OSTI ID:6766763

Davidson, D L

Research objectives under which this work was initiated were as follows: To understand the mechanisms of subcritical crack extension and fracture toughness in particulate-reinforced metal matrix composites projected for Naval applications in which one or more of these parameters control service. The factors thought to be important in 1985 were the processing variables by which these materials were fabricated and the role of SiC particles in altering fatigue crack growth and fracture toughness of the matrix alloys. The methods used in reaching for these objectives include the techniques of experimental micromechanics. Experiments in fatigue crack growth and fast fracture were conducted for a variety of composites obtained from different manufacturers, and these materials were thoroughly characterized. Materials characterized were picked in order to: (1) determine the effects of differences in matrix composition and heat treatment, (2) determine the effect of SiC volume fraction, and (3) account for differences in particle size. Materials were obtained from two different manufacturers. IN-9051+15v/o SiC (essentially Al-4Mg) and IN-9021+15v/o SiC, both made by mechanically alloying and powder metallurgy were obtained from Novamet. The remainder of the composites made by ingot metallurgy by Dural Aluminum Composites Co., were: Al-4Mg+15v/o SiC, 2014+15v/o SiC, 2014+25v/o SiC, 2024+15v/o, 2014+15v/o SiC, and 7475+15v/o SiC.

• Research Organization: Southwest Research Inst., San Antonio, TX (USA)
• OSTI ID: 6766763
• Report Number(s): AD-A-223863/2/XAB; CNN: N00014-85-C-0206
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360203* -- Ceramics
Cermets
& Refractories-- Mechanical Properties
ALLOYS
ALUMINIUM ALLOYS
CARBIDES
CARBON COMPOUNDS
CASTINGS
COMPOSITE MATERIALS
CRACK PROPAGATION
DOCUMENT TYPES
EQUIPMENT
FATIGUE
FRACTURE MECHANICS
HEAT TREATMENTS
MAGNESIUM ALLOYS
MATERIALS
MATRIX MATERIALS
MECHANICAL PROPERTIES
MECHANICS
METALLURGY
MILITARY EQUIPMENT
PARTICLE SIZE
PARTICLES
PARTICULATES
POWDER METALLURGY
PROCESSING
PROGRESS REPORT
REINFORCED MATERIALS
SILICON CARBIDES
SILICON COMPOUNDS
SIZE