The influence of laser glazing on fatigue crack growth in Ti-24Al-11Nb

Journal Article · Sat Jan 01 04:00:00 EST 1994 · Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States)

OSTI ID:5189720

Malakondaiah, G; Nicholas, T ^[1]

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1. Wright Lab., Wright-Patterson AFB, OH (United States)

The influence of laser glazing on fatigue crack growth (FCG) in a titanium aluminide (Ti[sub 3]Al) alloy Ti-24Al-11Nb has been studied. Glazing leads to retention of beta phase in the melt zone and is accompanied by a significant increase in hardness as compared to that of the base microstructure. Laser glazing strongly influences the FCG behavior. Crack growth rates (CGRs) at a given stress intensity are reduced by up to three orders of magnitude. Maximum retardation in the CGR is observe when the crack front is around 4.0 mm ahead of the laser track. The observed slowing of CGR can be understood on the basis of the superposition principle that accounts for the influence of residual stresses on FCG. The equilibrating compressive stresses resulting from the tensile thermal residual stresses reduce the local effective stress intensity and, thereby, lead to reduced CGRs. In the absence of residual stresses, when subjected to a thermal treatment (650[degree]C/100 h), no observable variation in CGR is noticed over the entire crack length that encompassed two laser tracks.

• OSTI ID: 5189720
• Journal Information: Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States), Journal Name: Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States) Vol. 25:1; ISSN 0360-2133; ISSN MTTABN
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101* -- Metals & Alloys-- Preparation & Fabrication
360103 -- Metals & Alloys-- Mechanical Properties
ALLOY SYSTEMS
ALLOYS
ALUMINIUM ALLOYS
CRACK PROPAGATION
DATA
ELECTROMAGNETIC RADIATION
EXPERIMENTAL DATA
INFORMATION
INTERMETALLIC COMPOUNDS
LASER RADIATION
NIOBIUM ALLOYS
NUMERICAL DATA
RADIATIONS
SURFACE TREATMENTS
TERNARY ALLOY SYSTEMS
TITANIUM ALLOYS
TITANIUM BASE ALLOYS