Matthew Peel - Academia.edu (original) (raw)

Papers by Matthew Peel

Materials Science Engineering a Structural Materials Properties Microstructure and Processing, Dec 1, 2006

Metallurgical and Materials Transactions a Physical Metallurgy and Materials Science 2006 37a 2183 2193, Jul 22, 2006

The aim of this study was to explore the so-called processing window, within which good-quality w... more The aim of this study was to explore the so-called processing window, within which good-quality welds can be produced, for the friction stir welding of AA5083 to AA6082. To that end a systematic set of nine instrumented welds were made using rotation speeds of 280, 560, and 840 rpm and traverse speeds of 100, 200, and 300 mm/min with AA5083 on the advancing side and another nine with the materials reversed. For comparison a smaller series of AA5083-AA5083 and AA6082-AA6082 welds were also made. Thermocouple measurements, tool torque, extent of material mixing, and macrostructural observations all indicate that the temperature under the tool is more strongly dependent on the rotation than the traverse speed. It was found that in the current case, the power (energy/s) and heat input (energy/mm) do not correlate simply with the weld temperature. As a result, such metrics may not be suitable for characterizing the conditions under which welds are produced.

Powder Diffraction, 2009

ABSTRACT Weld residual stress (RS) measurements are often undertaken on test-pieces which have be... more ABSTRACT Weld residual stress (RS) measurements are often undertaken on test-pieces which have been Cut Out from large components, yet it remains unclear to what extent the RSs in test-pieces are representative of those present in the original component. Similarly weld mechanical performance tests are frequently undertaken on cross-weld test-pieces without a proper understanding of the level or influence of retained RS. We present a systematic study of the relaxation of longitudinal RS in thin-plate butt welds produced using different materials and welding methods (FSW, laser-MIG, and pulsed-MIG). In each case the RSs were measured repeatedly in the same location as the welds were progressively and symmetrically cut down. Although cutting inevitably leads to stress redistribution, significant relaxation of the longitudinal RS was only observed when the weld length or width was reduced to below a certain value. This critical value appears to correlate with the lateral width of the tensile zone local to the weld-line and may be considered to be the characteristic length as defined in St. Venant's principle. Further, it was found that the level of stress relaxation as a function of weld length for all the welds studied could be collapsed onto a single empirical curve using a simple approach based on the characteristic length scales of the weld. Given the range of materials and welding methods used, this relation appears to be of general use for thin-plate welds although further work is required to test the limits of its applicability. (C) 2009 International Centre for Diffraction Data. [DOI: 10.1154/1.3152580]

Materials Science Forum, 2008

Abstract There have been many theoretical studies to predict the stress fields around the tip of ... more Abstract There have been many theoretical studies to predict the stress fields around the tip of a growing fatigue crack. However, until recently the highly-localized, small scale nature of the stresses has meant that direct measurement has not been possible. With the current ...

Materials Science Forum, 2008

Page 1. Synchrotron energy-dispersive X-ray diffraction analysis of residual strains around frict... more Page 1. Synchrotron energy-dispersive X-ray diffraction analysis of residual strains around friction welds between dissimilar aluminium and nickel alloys Tea-Sung Jun 1,a , Shu Yan Zhang 1,b , Mina Golshan 2,c , Matthew Peel 3,d , ...

Volume 5: High-Pressure Technology; ASME NDE Division; Rudy Scavuzzo Student Paper Symposium, 2013

ABSTRACT Tensile residual stress can reduce the load carrying capability of a structure. However,... more ABSTRACT Tensile residual stress can reduce the load carrying capability of a structure. However, residual stresses may be redistributed during the life of a component by, for example, permanent deformation. This paper explains an experiment carried out to understand how applied and residual stresses interact and to seek a method of measuring elastic follow-up during the interaction. A friction stir welded aluminium alloy plate was subjected to a series of incrementally increasing load and unload cycles, whilst simultaneously measuring residual stresses and deformation. In-situ loading of the specimen during the residual stress measurements allowed the relaxation of the residual stress to be quantified. The elastic follow-up has been estimated and measured by considering both the structural stiffnesses of the specimen and the relaxation of the residual stress. It was found that global yielding, which can result in no net change of incompatibility, has to be considered when calculating elastic follow-up. An estimation of the elastic follow-up factor based on the structural stiffnesses of the specimen was found to be non-conservative and an elastic follow-up factor of 2.9 was measured. That is three times as much plastic strain is required to relax the residual stress when compared to the fixed-displacement case.

Materials Science Forum, 2006

Abstract In this paper we discuss certain aspects of residual stress measurements using energy-di... more Abstract In this paper we discuss certain aspects of residual stress measurements using energy-dispersive synchrotron X-ray diffraction using very high X-ray energies in the range up to 200keV. In particular, we focus on the strain resolution and its relation to the ...

Powder Diffraction, 2009

Determination of residual stresses around blisters in Zr-2.5%Nb pressure tubes. [Powder Diffracti... more Determination of residual stresses around blisters in Zr-2.5%Nb pressure tubes. [Powder Diffraction 24, S72 (2009)]. Javier R. Santisteban, Axel Steuwer, Gladys Domizzi, Matthew J. Peel. Abstract. We have used synchrotron X ...

Materials Science Forum, 2012

ABSTRACT Residual stress measurements have been undertaken in a multi-pass circumferential double... more ABSTRACT Residual stress measurements have been undertaken in a multi-pass circumferential double J butt-weld made from a P92 martensitic steel pipe using an In625 superalloy weld metal. Stresses were evaluated in the as welded condition and after post weld heat treatment. The deep hole drilling and neutron diffraction techniques were used to provide through thickness measurements for the parent, weld metal and heat affected region for the as-welded and the post weld heat treated conditions. The use of multiple residual stress measurement techniques provides an understanding of the stress distributions as well as increasing confidence in the reliability of the measurements. The results presented are discussed with respect to the residual stress magnitude and location as well as with respect to the effectiveness of the post weld heat treatment procedure.

Materials Science Forum, 2013

ABSTRACT This paper presents a novel experiment to quantify both the initial residual stress stat... more ABSTRACT This paper presents a novel experiment to quantify both the initial residual stress state in a specimen and its redistribution due to plasticity induced by in-situ loading. The rate of relaxation of the residual stress with respect to permanent deformation is a measure of the elastic follow-up associated with the residual stress field. Residual stress measurements were made using high energy dispersive X-ray diffraction. Digital image correlation was used to measure full-field deformation on the specimen, verified by strain gauges. The specimen was loaded/unloaded in-situ incrementally to promote plasticity, allowing the relaxation rate of the residual stress to be quantified. An elastic follow-up factor, ZZZ, of 2 was calculated for the residual stress field, indicating loading conditions of the residual stress field between fixed-displacement and fixed-load.

Science and Technology of Welding and Joining, 2012

ABSTRACT The joining of dissimilar materials is attaining increasing importance as there is a dri... more ABSTRACT The joining of dissimilar materials is attaining increasing importance as there is a drive to utilise hybrid structures and reduce the weight or cost of products. The present work therefore studied the linear friction welding of commercially pure grades of aluminium to copper (AA 1050 to C101) for potential power transmission applications. Results showed that welds with very good mechanical and electrical properties can be produced. The weld microstructure was analysed using optical microscopy, backscattered scanning electron microscopy, hardness testing and high energy synchrotron X-ray diffraction. These techniques were used in order to identify any cross-weld grain size variations and possible formation of intermetallic phases close to the weld line.

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2010

Recent advances in synchrotron based X-ray imaging and diffraction techniques offer interesting n... more Recent advances in synchrotron based X-ray imaging and diffraction techniques offer interesting new possibilities for mapping 3D grain shapes and crystallographic orientations in different classes of polycrystalline materials. X-ray diffraction contrast tomography (DCT) is a monochromatic beam imaging technique combining the principles of X-ray micro-tomography and three-dimensional X-ray diffraction microscopy (3DXRD). DCT provides simultaneous access to 3D grain shape, crystallographic

Metallurgical and Materials Transactions A, 2008

The extent to which in-situ global mechanical tensioning (GMT) can be used to modify the residual... more The extent to which in-situ global mechanical tensioning (GMT) can be used to modify the residual stress state in friction stir (FS) welds is investigated in this article. Residual stress distributions have been determined by synchrotron X-ray and neutron diffraction for four sets of FS welds in high-strength AA7449-W51 and lithium containing AA2199-T8 aerospace aluminum alloys subjected to a systematic

Materials Science and Engineering: A, 2006

Materials Science and Engineering: A, 2008

Materials Science Engineering a Structural Materials Properties Microstructure and Processing, Dec 1, 2006

Metallurgical and Materials Transactions a Physical Metallurgy and Materials Science 2006 37a 2183 2193, Jul 22, 2006

The aim of this study was to explore the so-called processing window, within which good-quality w... more The aim of this study was to explore the so-called processing window, within which good-quality welds can be produced, for the friction stir welding of AA5083 to AA6082. To that end a systematic set of nine instrumented welds were made using rotation speeds of 280, 560, and 840 rpm and traverse speeds of 100, 200, and 300 mm/min with AA5083 on the advancing side and another nine with the materials reversed. For comparison a smaller series of AA5083-AA5083 and AA6082-AA6082 welds were also made. Thermocouple measurements, tool torque, extent of material mixing, and macrostructural observations all indicate that the temperature under the tool is more strongly dependent on the rotation than the traverse speed. It was found that in the current case, the power (energy/s) and heat input (energy/mm) do not correlate simply with the weld temperature. As a result, such metrics may not be suitable for characterizing the conditions under which welds are produced.

Powder Diffraction, 2009

ABSTRACT Weld residual stress (RS) measurements are often undertaken on test-pieces which have be... more ABSTRACT Weld residual stress (RS) measurements are often undertaken on test-pieces which have been Cut Out from large components, yet it remains unclear to what extent the RSs in test-pieces are representative of those present in the original component. Similarly weld mechanical performance tests are frequently undertaken on cross-weld test-pieces without a proper understanding of the level or influence of retained RS. We present a systematic study of the relaxation of longitudinal RS in thin-plate butt welds produced using different materials and welding methods (FSW, laser-MIG, and pulsed-MIG). In each case the RSs were measured repeatedly in the same location as the welds were progressively and symmetrically cut down. Although cutting inevitably leads to stress redistribution, significant relaxation of the longitudinal RS was only observed when the weld length or width was reduced to below a certain value. This critical value appears to correlate with the lateral width of the tensile zone local to the weld-line and may be considered to be the characteristic length as defined in St. Venant's principle. Further, it was found that the level of stress relaxation as a function of weld length for all the welds studied could be collapsed onto a single empirical curve using a simple approach based on the characteristic length scales of the weld. Given the range of materials and welding methods used, this relation appears to be of general use for thin-plate welds although further work is required to test the limits of its applicability. (C) 2009 International Centre for Diffraction Data. [DOI: 10.1154/1.3152580]

Materials Science Forum, 2008

Abstract There have been many theoretical studies to predict the stress fields around the tip of ... more Abstract There have been many theoretical studies to predict the stress fields around the tip of a growing fatigue crack. However, until recently the highly-localized, small scale nature of the stresses has meant that direct measurement has not been possible. With the current ...

Materials Science Forum, 2008

Page 1. Synchrotron energy-dispersive X-ray diffraction analysis of residual strains around frict... more Page 1. Synchrotron energy-dispersive X-ray diffraction analysis of residual strains around friction welds between dissimilar aluminium and nickel alloys Tea-Sung Jun 1,a , Shu Yan Zhang 1,b , Mina Golshan 2,c , Matthew Peel 3,d , ...

Volume 5: High-Pressure Technology; ASME NDE Division; Rudy Scavuzzo Student Paper Symposium, 2013

ABSTRACT Tensile residual stress can reduce the load carrying capability of a structure. However,... more ABSTRACT Tensile residual stress can reduce the load carrying capability of a structure. However, residual stresses may be redistributed during the life of a component by, for example, permanent deformation. This paper explains an experiment carried out to understand how applied and residual stresses interact and to seek a method of measuring elastic follow-up during the interaction. A friction stir welded aluminium alloy plate was subjected to a series of incrementally increasing load and unload cycles, whilst simultaneously measuring residual stresses and deformation. In-situ loading of the specimen during the residual stress measurements allowed the relaxation of the residual stress to be quantified. The elastic follow-up has been estimated and measured by considering both the structural stiffnesses of the specimen and the relaxation of the residual stress. It was found that global yielding, which can result in no net change of incompatibility, has to be considered when calculating elastic follow-up. An estimation of the elastic follow-up factor based on the structural stiffnesses of the specimen was found to be non-conservative and an elastic follow-up factor of 2.9 was measured. That is three times as much plastic strain is required to relax the residual stress when compared to the fixed-displacement case.

Materials Science Forum, 2006

Abstract In this paper we discuss certain aspects of residual stress measurements using energy-di... more Abstract In this paper we discuss certain aspects of residual stress measurements using energy-dispersive synchrotron X-ray diffraction using very high X-ray energies in the range up to 200keV. In particular, we focus on the strain resolution and its relation to the ...

Powder Diffraction, 2009

Determination of residual stresses around blisters in Zr-2.5%Nb pressure tubes. [Powder Diffracti... more Determination of residual stresses around blisters in Zr-2.5%Nb pressure tubes. [Powder Diffraction 24, S72 (2009)]. Javier R. Santisteban, Axel Steuwer, Gladys Domizzi, Matthew J. Peel. Abstract. We have used synchrotron X ...

Materials Science Forum, 2012

ABSTRACT Residual stress measurements have been undertaken in a multi-pass circumferential double... more ABSTRACT Residual stress measurements have been undertaken in a multi-pass circumferential double J butt-weld made from a P92 martensitic steel pipe using an In625 superalloy weld metal. Stresses were evaluated in the as welded condition and after post weld heat treatment. The deep hole drilling and neutron diffraction techniques were used to provide through thickness measurements for the parent, weld metal and heat affected region for the as-welded and the post weld heat treated conditions. The use of multiple residual stress measurement techniques provides an understanding of the stress distributions as well as increasing confidence in the reliability of the measurements. The results presented are discussed with respect to the residual stress magnitude and location as well as with respect to the effectiveness of the post weld heat treatment procedure.

Materials Science Forum, 2013

ABSTRACT This paper presents a novel experiment to quantify both the initial residual stress stat... more ABSTRACT This paper presents a novel experiment to quantify both the initial residual stress state in a specimen and its redistribution due to plasticity induced by in-situ loading. The rate of relaxation of the residual stress with respect to permanent deformation is a measure of the elastic follow-up associated with the residual stress field. Residual stress measurements were made using high energy dispersive X-ray diffraction. Digital image correlation was used to measure full-field deformation on the specimen, verified by strain gauges. The specimen was loaded/unloaded in-situ incrementally to promote plasticity, allowing the relaxation rate of the residual stress to be quantified. An elastic follow-up factor, ZZZ, of 2 was calculated for the residual stress field, indicating loading conditions of the residual stress field between fixed-displacement and fixed-load.

Science and Technology of Welding and Joining, 2012

ABSTRACT The joining of dissimilar materials is attaining increasing importance as there is a dri... more ABSTRACT The joining of dissimilar materials is attaining increasing importance as there is a drive to utilise hybrid structures and reduce the weight or cost of products. The present work therefore studied the linear friction welding of commercially pure grades of aluminium to copper (AA 1050 to C101) for potential power transmission applications. Results showed that welds with very good mechanical and electrical properties can be produced. The weld microstructure was analysed using optical microscopy, backscattered scanning electron microscopy, hardness testing and high energy synchrotron X-ray diffraction. These techniques were used in order to identify any cross-weld grain size variations and possible formation of intermetallic phases close to the weld line.

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2010

Recent advances in synchrotron based X-ray imaging and diffraction techniques offer interesting n... more Recent advances in synchrotron based X-ray imaging and diffraction techniques offer interesting new possibilities for mapping 3D grain shapes and crystallographic orientations in different classes of polycrystalline materials. X-ray diffraction contrast tomography (DCT) is a monochromatic beam imaging technique combining the principles of X-ray micro-tomography and three-dimensional X-ray diffraction microscopy (3DXRD). DCT provides simultaneous access to 3D grain shape, crystallographic

Metallurgical and Materials Transactions A, 2008

The extent to which in-situ global mechanical tensioning (GMT) can be used to modify the residual... more The extent to which in-situ global mechanical tensioning (GMT) can be used to modify the residual stress state in friction stir (FS) welds is investigated in this article. Residual stress distributions have been determined by synchrotron X-ray and neutron diffraction for four sets of FS welds in high-strength AA7449-W51 and lithium containing AA2199-T8 aerospace aluminum alloys subjected to a systematic

Materials Science and Engineering: A, 2006

Materials Science and Engineering: A, 2008