Characterisation of elastic and plastic deformation in a nickel superalloy using pulsed neutrons

Ezeilo, A.N.; Webster, G. A.; Webster, Peter J.; Wang, X.

doi:10.1016/0921-4526(92)90546-5

Cited by 20 publications

(11 citation statements)

References 4 publications

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“…The major complicating factor associated with the diffraction strain measurement approach is caused by anisotropy in the elastic and plastic response of grains in different orientations, and the peak overlap associated with a multicomponent microstructure comprised of γ, δ, γ´ and γ´´. However, a number of studies [4,5] have shown that for IN718 it is reasonable to simply apply a Reitveld fit of a single lattice parameter a to the entire diffraction spectrum obtained and then to use the bulk engineering elastic constants for the conversion of the measured lattice strains to macroscopic stress. These assumptions were consistent with the microstructure of the as-quenched forging.…”

Section: Methodsmentioning

confidence: 99%

Modeling and Measurement of Residual Stresses in a Forged IN718 Superalloy Disc

Dye

Roder

Tin

et al. 2004

Superalloys 2004 (Tenth International Symposium)

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The residual stresses present in a quenched IN718 aeroengine compressor disc forging have been characterized using neutron diffraction and the results compared to those obtained from a finite element (FE) model for the quenching process. The ~40 kg forging had a diameter of 400 mm and a maximum thickness of ~45mm. Neutron path lengths of up to 60 mm were required to record strain components at the deepest points within the material. The residual hoop and radial stresses measured are generally compressive at the surface, up to 600 MPa and tensile at depth, up to 400 MPa, whilst the radial stresses are generally small. The deviatoric stresses are generally <150 MPa. FE model predictions of the residual stress are reasonable agreement with the measured values.

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Section: Methodsmentioning

confidence: 99%

Modeling and Measurement of Residual Stresses in a Forged IN718 Superalloy Disc

Dye

Roder

Tin

et al. 2004

Superalloys 2004 (Tenth International Symposium)

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“…3, illustrate further an effect observed by Ezeilo et al (12). Heterogeneous deformation in the steel samples gives rise to significant peak shifts on specific crystallographic planes indicating the presence of plastic strains.…”

Section: Discussionmentioning

confidence: 67%

“…Earlier (11) The MS was received on 6 November 1995 and was accepted for publication on 13 September 1996. influence of prestrain on the neutron diffraction peak angle width for an aluminium alloy was examined. Studies by Ezeilo et al (12) demonstrated that prior plastic strain introduced heterogeneous deformation and consequently internal residual strains were introduced on specific crystallographic planes after unloading. In this paper the measurement and analysis of prior plastic strain in an aluminium alloy weld and cracked ferritic steel beams are presented.…”

Section: Introductionmentioning

confidence: 98%

The measurement of prior plastic deformation in metallic alloys using the neutron diffraction technique

Smith

Webster

1997

The Journal of Strain Analysis for Engineering Design

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The neutron diffraction technique has been used to determine the extent of prior plastic deformation in an aluminium alloy weld and preloaded cracked steel beams. The change in peak width has been shown to be a function of the prior plastic deformation, and is found to be insensitive to the direction of prior straining, material and the orientation of the diffraction vector. Prior plastic deformation has also been shown to influence the reference peak angle. The distributions of prior plastic strain in the steel cracked beam subjected to an overload were found to be in good agreement with results from finite element analyses.

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“…Table I shows the DECs and intergranular stresses (cqr) obtained from experiments and calculations on a nickel base superalloy. The experiments were performed on PEARL at ISIS (UK) using a stress rig in situ while the calculations were made using the SCECs of pure nickel (Ezeilo et al, 1992).…”

Section: Diffraction Elastic Constants (Decs)mentioning

confidence: 99%

“…crystal reflection was used, which appears to be relatively insensitive to the build-up of intergranular stresses (Ezeilo et al, 1992 Fig. 4 showing compressive stresses at the surface close to the yield stress of the material.…”

Section: Shallow Stress Gradientsmentioning

confidence: 99%

Advances in Neutron Diffraction for Engineering Residual Stress Measurements

Ezeilo

Webster

1999

Texture, Stress, and Microstructure

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The increasing awareness amongst engineers and designers, of the significance of residual stresses in influencing the useful lifetimes ofengineering components, has resulted in more demanding expectations being placed on the methods used to obtain these stresses. The neutron diffraction technique is emerging as the most attractive measuring method as the residual stresses can usually be obtained non-destructively to depths of up to 40 mm in some common engineering materials. Although it is a relatively new technique it has been used to measure the residual stresses in a range of engineering materials introduced by a wide variety of manufacturing processes such as welding, quenching, machining, shot peening, cold hole expansion and autofrettage.In this paper the neutron diffraction technique for non-destructive residual stress measurements will be described including methods used to validate the measurements. Precautions that should be taken in order to obtain reliable measurements are outlined. Procedures being investigated in order to produce a code of practice will be presented.A representative selection of stress distributions developed by a range of manufacturing processes is examined. Some comparisons are made with strain gauge, X-ray and numerical predictions. It is shown how the results can be of benefit in engineering stress analysis.

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Characterisation of elastic and plastic deformation in a nickel superalloy using pulsed neutrons

Cited by 20 publications

References 4 publications

Modeling and Measurement of Residual Stresses in a Forged IN718 Superalloy Disc

Modeling and Measurement of Residual Stresses in a Forged IN718 Superalloy Disc

The measurement of prior plastic deformation in metallic alloys using the neutron diffraction technique

Advances in Neutron Diffraction for Engineering Residual Stress Measurements

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