Fatigue Characterization of Functionally Graded Metallic Alloys

Journal Article · Fri Feb 15 04:00:00 EST 2008 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2896817· OSTI ID:21055256

Silva, F S ^[1]

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1. Mechanical Engineering Department, School of Engineering, Minho University, Campus de Azurem, 4800-058 Guimaraes (Portugal)

Functionally graded components exhibit spatial variations of mechanical properties in contrast with, and as an alternative to, purely homogeneous components. A large class of graded materials, however, are in fact mostly homogeneous materials with property variations (chemical or mechanical) restricted to a specific area or layer produced by applying for example a coating or by introducing sub-surface residual stresses. However, it is also possible to obtain graded materials with a smooth transition of mechanical properties along the entire component, for example in a 40 mm component. This is possible, for example, by using centrifugal casting technique or incremental melting and solidification technique. In this paper we will study fully metallic functionally graded components with a smooth gradient, focusing on fatigue crack propagation. Fatigue propagation will be assessed in the direction parallel to the gradation (in different homogeneous layers of the functionally graded component) to assess what would be fatigue crack propagation on the direction perpendicular to the gradation. Fatigue crack growth rate (standard mode I fatigue crack growth) will be correlated to the mode I stress intensity factor range. Other mechanical properties of different layers of the component (Young's modulus) will also be considered in this analysis. The effect of residual stresses along the component gradation on crack propagation will also be taken into account. A qualitative analysis of the effects of some important features, present in functionally graded materials, will be made based on the obtained results.

• OSTI ID: 21055256
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 973; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALLOYS
CRACK PROPAGATION
CRACKS
FATIGUE
LAYERS
MELTING
MODIFICATIONS
RESIDUAL STRESSES
SOLIDIFICATION
STRESS INTENSITY FACTORS
SURFACES
VARIATIONS
YOUNG MODULUS