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X-ray Microtomography of Fatigue Crack Closure as a Function of Applied Load In Al-Li 2090 T8E41 Samples

Published online by Cambridge University Press:  10 February 2011

R. Morano ,
S.R. Stock ,
G.R. Davis  and
J.C. Elliott
R. Morano
Affiliation:
School of Materials Sci. & Eng. And Mechanical Properties Res. Lab., Georgia Institute of Technology, Atlanta, Ga 30332-0245, USA. stuart.stock@mse.gatech.edu
S.R. Stock
Affiliation:
School of Materials Sci. & Eng. And Mechanical Properties Res. Lab., Georgia Institute of Technology, Atlanta, Ga 30332-0245, USA. stuart.stock@mse.gatech.edu
G.R. Davis
Affiliation:
Dept. Of Biophysics in Relation to Dentistry, Queen Mary and Westfield College, London UK
J.C. Elliott
Affiliation:
Dept. Of Biophysics in Relation to Dentistry, Queen Mary and Westfield College, London UK
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Abstract

Crack closure is held to be responsible for very low fatigue crack growth rates in many alloys such as Al-Li 2090 T8E41, and early crack face contact during unloading or prolonged contact during loading seems to reduce the driving “force” for crack extension. High resolution x-ray computed tomography (i.e., microtomography) allows one to image the entire volumes of samples and to quantify opening as a function of applied load over the entire crack surface. Crack closure results are reported for a fatigue crack grown under load ratio R=0.1 in a compact tension sample of Al-Li 2090 T8E41; the crack was free to choose its path unconstrained by side-grooves which are normally used to suppress crack deflection. The inter-relationship between crack path, crack face contact and applied load level are discussed.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 591 , 1999 , 31
Copyright
Copyright © Materials Research Society 2000

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