Journal of Neutron Research - Volume 9, issue 2-4

Authors: Steuwer, A. | Withers, P.J. | Santisteban, J.R. | Edwards, L. | Fitzpatrick, M.E. | Daymond, M.R. | Johnson, M.W.

Article Type: Research Article

Abstract: The transmission spectrum of thermal neutrons through polycrystalline samples as a function of wavelength displays sudden increases in intensity known as Bragg edges. These edges occur whenever the wavelength ceases to fulfil the Bragg condition for coherent scattering at Bragg angle 2Θ = 180°. The shape and position of these edges contain information about the stress state present in the sample. The transmission method has two key advantages over conventional neutron diffraction. For samples with essentially one or two-dimensional stress-fields the use of pixellated detector arrays enables simultaneous, therefore very fast, spatial imaging of strains. At the same time it …allows for the determination of the unstrained lattice spacing as well as stresses in the sample by evaluating a set of strain images taken at different sample inclinations, similar to the sin2 Ψ-technique of X-ray diffraction. We show how this technique has been successfully employed to determine accurately the unstrained lattice parameter and stresses in bi-axially stressed samples. Show more

Keywords: Neutron transmission, Sin2 Ψ, method, Strain, Stress

DOI: 10.1080/10238160108200154

Citation: Journal of Neutron Research, vol. 9, no. 2-4, pp. 289-294, 2001

Authors: Ono, M. | VráNa, M. | Torii, S. | Tayo, T. | Olkawa, K. | Kamiyama, T. | Waku, Y. | Fukunaga, T. | Suzuki, K. | Mikula, P. | Lukáš, P.

Article Type: Research Article

Abstract: Bragg diffraction angle analysis with a high-resolution strain diffractometer and time-of-flight analysis with backscattering powder diffractometer were complementarily applied to neutron residual strain investigations in an ultra-high temperature resistant composite of eutectic two-phase Al2 O3 /Y3 A15 O12 (YAG) single-crystal. It was found that the YAG phase was in tension and the A12 O3 phase was in compression which resulted in strains ε in the range of ∼10−4 at room temperature, when the measured lattice spacings of the sintered YAG and sintered Al2 O3 w ere used as the reference values of strain-free materials. Discussions are …given on the methodological points of both analyses with respect to evaluation of a strain value for each phase in the two-phase single crystal materials. Show more

Keywords: Ductile composite, Single crystals Al2OS3/YAG, High temperature resistant materials, Strain measurement: Neutron diffraction

DOI: 10.1080/10238160108200155

Citation: Journal of Neutron Research, vol. 9, no. 2-4, pp. 295-304, 2001

Authors: Albertini, Gianni | Peng, Ru Lin | Manescu, Adrian | Ponzetti, Araldo

Article Type: Research Article

Abstract: As part of an integral study on operation and safety of centrifuges for food processing and agricultural applications, neutron diffraction measurement was carried out on a bowl (rotor of a centrifuge) to investigate residual stresses due to manufacturing. The bowl was made of duplex stainless steel containing 50 vol% austenite and 50 vol% ferrite. The results reveal high tensile stresses in the austenite phase and high compressive stresses in the ferrite phase. In addition, significant macroscopic stresses were observed in the hoop direction, which decreased with increasing distance from the upper surface of the bowl. The observed residual stresses were …attributed to different processes employed during manufacturing. Show more

Keywords: Residual stress, Neutron diffraction, Duplex steel, Centrifuges

DOI: 10.1080/10238160108200156

Citation: Journal of Neutron Research, vol. 9, no. 2-4, pp. 305-312, 2001

Authors: Lavelle, B. | Vendier, L. | Guiraud, L.

Article Type: Research Article

Abstract: In order to compare bulk and surface elastic coefficients, transmission and reflection measurements have been performed using synchrotron radiation. A pure Ni sample submitted to different levels of stress has been studied. The spectral analysis of the diffracted beam allows us to determine the strain for a given crystalline plane, with a precision in the range of goniometric X-ray analysis. From the strain Mohr circle and the sin2 Ψ law, the elastic characteristics for each studied crystalline plane can be deduced. We find significant differences between bulk and surface elastic coefficients.

Keywords: Transmission and reflection, Synchrotron radiation, Elastic constants, Diffracted beam

DOI: 10.1080/10238160108200157

Citation: Journal of Neutron Research, vol. 9, no. 2-4, pp. 313-317, 2001

Authors: Cherouat, A. | Gong, X.L. | Sicot, O. | Lu, J.

Article Type: Research Article

Abstract: The cooling condition in the forming process (resin transfer molding (RTM), structural resin injection molding (SRIM), laying-up) plays an important part in residual stress distribution in the advanced composite pieces. The residual stresses, which are induced during the cool-down process following high temperature consolidation, result from the coefficient of thermal expansion (CTE) mismatch between plies. This paper describes the development of a finite element method to simulate the prediction of residual stresses and strains fields induced by cool-down process. In this research we used incremental hole drilling method combined with acoustic emission to understand the chronology of damage events, the …development of damage modes (matrix cracks, laminate delamination and fibers fractures). The laminate plates [02 /902 ]s , was polymerized with three different cooling conditions (fast, normal and slow). Specimens cut from these plates were tested to measure their tensile strength and to investigate the influence of residual stresses on the mechanical behavior of laminate structures. Show more

Keywords: Laminate composites, Residual stress, Hole drilling method, Forming process, Finite element analysis

DOI: 10.1080/10238160108200158

Citation: Journal of Neutron Research, vol. 9, no. 2-4, pp. 319-330, 2001

Authors: Wang, Y.D. | Lin Peng, R. | Mcgreevy, R.L.

Article Type: Research Article

Abstract: A high anisotropy for grain orientation dependent residual stress, or inter-granular stress, was previously found for the austenite and deformation-induced martensite in a cold-rolled 301 stainless steel. This paper focuses on the changes of both macroscopic residual stress and inter-granular residual stress in both phases after annealing at 500°C for 2 h. Such a detailed analysis of the relaxation of anisotropic residual stresses, induced by annealing, can provide insights into the mechanism of anisotropic recovery for different orientated grains/texture components.

Keywords: Residual stress, Neutron diffraction, Stainless steel, Anisotropy, Annealing, Recovery

DOI: 10.1080/10238160108200159

Citation: Journal of Neutron Research, vol. 9, no. 2-4, pp. 331-336, 2001

Authors: Montay, G. | Cherouat, A. | Lu, J.

Article Type: Research Article

Abstract: Shot peening is a surface deformation process that can produce very large improvements in fatigue performance, stress corrosion …  of engineering components. This treatment involves modifications of the surface and subsurface condition of a material that can be described by the change of residual stress. The aim of this study is to measure the residual stress gradient introduced by the shot peening in a titanium alloy TA6V. A lot of techniques are available today with their advantages and disadvantages. In this paper, we will compare two methods, which are the X-ray technique and the incremental hole drilling method.

Keywords: Residual stress, Shot peening, Hole drilling method, X-ray technique, Titanium alloy

DOI: 10.1080/10238160108200160

Citation: Journal of Neutron Research, vol. 9, no. 2-4, pp. 337-344, 2001

Authors: Steuwer, A. | Withers, P.J. | Burguete, R.

Article Type: Research Article

Abstract: Neutron and synchrotron radiation have been employed to create 2D maps of the variation of strains and the unstrained lattice spacing d0 in longitudinal and transverse direction over a cross-section of a friction stir weld (FSW) of an aluminium alloy AA-2024. Strains have been measured directly in the FSW using neutrons. The variation of the unstrained lattice parameter has been measured with synchrotrons on specially prepared stress-relaxed ‘combs’ of the original weld. The variation of d0 across the weld varies on the same scale as the strains on a magnitude of ∼ l000 µε thus influencing greatly the …magnitude of inferred residual stresses in the sample. Both the d0 variation and strain map show detailed features reflecting the characteristic microstructure generated during the welding process. In particular, they are asymmetric about the weld centre-line. The dominant longitudinal residual stress field is tensile beneath the edge of the tool and compressive in the weld centre-line. Transverse stresses are smaller by a factor of 3 and tend to be compressive. Stresses measured by diffraction agree well with results from conventional holedrilling performed in the same sample. Show more

Keywords: Neutron, Synchrotron, Strain, Stress, Friction stir weld

DOI: 10.1080/10238160108200161

Citation: Journal of Neutron Research, vol. 9, no. 2-4, pp. 345-350, 2001

Authors: Asserin, O. | Braham, C. | Lodini, A.

Article Type: Research Article

Abstract: The F82-H modified martensitic steel is currently one of the best options for the first wall of future fusion reactors. Martensitic steel samples of F82-H (0.1 C; 8 Cr; 2 W; 0.2 V; 0.1 Mn; 0.1 Si wt %) have been electron beam welded. Strain analysis by classical X-ray, synchrotron and neutron diffraction were carried out at different distances from the weld centre (0, 1, 2, 3, 4 and 5 mm). Strain and stress calculations require the determination of the exact unstressed lattice parameter (d0 ), which is determined by XRD. Material characterization and line broadening measurements by X-rays and …neutrons were performed. The integral breadth values measured by X-rays and neutrons coincide and can be compared to the micro-hardness profile. Show more

Keywords: Synchrotron, Neutron, X-ray, Residual stress, Diffraction, Line broadening

DOI: 10.1080/10238160108200162

Citation: Journal of Neutron Research, vol. 9, no. 2-4, pp. 351-356, 2001

Authors: Guezou, J.C. | Ceretti, M. | Baudin, T. | Mathon, M.H. | Penelle, R.

Article Type: Research Article

Abstract: The residual elastic strains determination by neutron diffraction has been performed on quartzite samples from a former texture study. The measured complete residual strain tensor has been considered as representative of the “natural” finite plastic deformation. Such tensors fitted to plastic tensors have been introduced in texture modelings. The results demonstrate the potential of complete and meaningful strain tensor determinations in rocks.

Keywords: Neutron diffraction, Residual elastic strain, Quartzite, Strain tensor, Texture, Modeling

DOI: 10.1080/10238160108200163

Citation: Journal of Neutron Research, vol. 9, no. 2-4, pp. 357-362, 2001

Authors: Seong, B.S. | Shin, E. | Lee, C.H. | Em, V.T. | Shim, H.S.

Article Type: Research Article

Abstract: Neutron intensities of the main wavelength (λ), the second-order (λ/2) and the third-order (λ/3) components in the Ge(113) reflecJed reactor beam were measured by the time-of-flight method for wavelength λ from 1.6 up to 2.41 Å. The measurements have been made as a function of the azimuthal angle Ψ of a Ge(113) monochromator rotation around the scattering vector. It is shown that the secondorder component caused by multiple diffraction is present over a wide interval of angle Ψ and its maximum value increases with wavelength. The second-order contamination can be avoided or decreased by the proper orientation of the monochromator.

Keywords: Multiple diffraction, Ge monochromator, Second-order contamination, Neutron diffraction

DOI: 10.1080/10238160108200164

Citation: Journal of Neutron Research, vol. 9, no. 2-4, pp. 363-371, 2001

Authors: Pang, J.W.L. | Rauchs, G. | Withers, P.J. | Bonner, N.W. | Twigg, E.S.

Article Type: Research Article

Abstract: Residual strain measurements have been carried out on a fibre reinforced Ti-6Al-4V (Ti-6-4) ring upon fabrication and after machining. As the composite is embedded in Ti-6-4 cladding, neutron diffraction is the only non-destructive technique able to measure residual strains within the composite region. Experimental results indicate that measurements can be made as far as 10 mm below the surface using a large gauge volume and long count times. An axisymmetric finite element model has been constructed, to predict the residual stress state on cooling from consolidation phase and after machining, which incorporates thermal, elastic and creep properties of the constituent …materials. Model predictions are in good agreement with experiments. Show more

Keywords: Titanium, Metal matrix composite, Residual stress, Finite element modelling

DOI: 10.1080/10238160108200165

Citation: Journal of Neutron Research, vol. 9, no. 2-4, pp. 373-379, 2001

Authors: Kőszegi, L.

Article Type: Research Article

Abstract: The outline of a new instrument is described that is dedicated to stress diffractometry at the Budapest Research Reactor (BRR). The first check of the instrument is planned at the beginning of 2001.

Keywords: Stress diffractometry, Neutron diffractometer, Instrument, Research

DOI: 10.1080/10238160108200166

Citation: Journal of Neutron Research, vol. 9, no. 2-4, pp. 381-384, 2001

Authors: Marmeggi, J.-CL.

Article Type: Research Article

Abstract: Neutron diffraction has the potential to provide information deep below the surface of real materials. Both mechanical and thermal loading are considered. Firstly the experimental set up to realise the uniaxial stress is described. Samples of NiO and alpha-uranium were submitted to an external uniaxial stress that gives complementary information in neutrons and X-rays scattering. Reversible or displacive phase transformations take place reversibly through the transition. Finally for high spatial resolution stress it would be necessary to use high energy X-ray synchrotron facilities to optimise effectively the stress rig.

Keywords: Compressive device, Mechanical loading, Structural phase transitions, Diffractometer

DOI: 10.1080/10238160108200167

Citation: Journal of Neutron Research, vol. 9, no. 2-4, pp. 385-391, 2001

Authors: Labbé, E. | Poisson, N. | Prioul, C. | Lodini, A.

Article Type: Research Article

Abstract: The railway industry is interested in studying the stress field at the interface between a railway wheel and its press fitted axle. The neutron diffraction technique provides a powerful tool for stress field investigations deep within the material. But the distance of neutron penetration is too high. For neutron diffraction strain measurements, a new method is proposed, involving drilling access holes to minimise the neutron path length within the material. The first step consists of determining the high-concentrated stress zone and of determining the influence of the drilling parameters on the stress. The second step is to perform neutron diffraction …strain measurements. These measurements gave some elastic micro-strain values at the wheel/axle interface whose are of the same order of the values obtained by numerical simulation. Values are in good agreement with each other with a gap of 80 µε, which is near to the neutron diffraction technique sensitivity. Show more

Keywords: Neutron diffraction, Strain measurements, Numerical simulation, Stress field

DOI: 10.1080/10238160108200168

Citation: Journal of Neutron Research, vol. 9, no. 2-4, pp. 393-397, 2001

Authors: Stefanescu, D. | Bouzina, A. | Dutta, M. | Wang, D.Q. | Fitzpatrick, M.E. | Edwards, L.

Article Type: Research Article

Abstract: Comparative stress measurements using neutron and X-ray data from an FTI 4% cold expanded hole in 7050 T76 aluminium alloy plate are presented. Good agreement is found between neutron and X-ray diffraction results. In combination, these results can be used to follow the effects of a −30kN under-load on the stress field around a cold expanded hole. This underload increases the depth of the compressive layer adjacent to the bore of the hole but reduces the value of the peak compressive stress.

Keywords: Neutron diffraction, X-ray diffraction, Residual stress, Cold expansion

DOI: 10.1080/10238160108200169

Citation: Journal of Neutron Research, vol. 9, no. 2-4, pp. 399-403, 2001

Authors: Turquier, F. | Stanic, V. | Ceretti, M. | Fitch, A. | Lodini, A. | Rustichelli, F.

Article Type: Research Article

Abstract: The present paper describes a study that attempts to develop the use of thermal barrier coatings for industrial foundry applications. A wide range of tool steel specimens coated with plasma-sprayed, thermal barrier ceramics having different compositions were tested in thermal fatigue by repeated immersion in liquid aluminium. Then, residual stress measurements performed by neutron diffraction on specimens coated with the ceramic that exhibited the longest thermal fatigue life showed the evolution of the residual stress profiles in the near-interface layers of the substrate. Synchrotron radiation measurements were attempted in the coating and in the vicinity of the interface.

Keywords: Residual stress, Neutron diffraction, Synchrotron radiation, Thermal barrier coatings

DOI: 10.1080/10238160108200170

Citation: Journal of Neutron Research, vol. 9, no. 2-4, pp. 405-409, 2001

Authors: Tarasiuk, J. | Wierzbanowski, K. | Kostrzewa, M. | Peczkis, B.

Article Type: Research Article

Abstract: The elastic response of the material and hence the internal stress behaviour can be modified and improved by an appropriate crystallographic texture optimisation. The question is: which texture should have a sample in order to assure the best elastic properties (e.g. in the sense of stored internal stresses)? The genetic algorithm method was applied to solve this problem in the present work.

Keywords: Elastic constants, Crystallographic texture, Genetic algorithm method, Elastic properties

DOI: 10.1080/10238160108200171

Citation: Journal of Neutron Research, vol. 9, no. 2-4, pp. 411-414, 2001

Authors: Luk´š, P. | Tomota, Y. | Harjo, S. | Neov, D. | Strunz, P. | Mikula, P.

Article Type: Research Article

Abstract: The strengthening mechanism of heavily cold-drawn pearlitic steel wires was studied using the high-resolution neutron diffraction experiment performed in situ upon tensile deformation. Microstructural parameters of lattice strain, microstrain and coherent block size, the evolution of which evidences the deformation mechanism of this ultrahigh strength steel, were extracted from the position, width and shape of the in situ recorded neutron diffraction profiles, respectively, using a newly proposed method of profile shape analysis. It was found that the deformation mechanism of cold-drawn pearlitic steel wires resembles the behavior of nanocrystalline materials.

Keywords: In situ high resolution neutron diffraction, Profile analysis, Pearlitic steel, Tensile deformation

DOI: 10.1080/10238160108200172

Citation: Journal of Neutron Research, vol. 9, no. 2-4, pp. 415-421, 2001

Authors: Stuhr, U.

Article Type: Research Article

Abstract: The new time-of-flight diffractometer for strain-field measurements POLDI at the continuous spallation source SINQ at PSI is presented. High intensity and high resolution are achieved simultaneously by allowing pulse overlapping. The dependence of the arrival time of the neutrons in the detector on the scattering angle allows the calculation of the diffraction pattern. The basic concept and the main instrument components are presented in this paper.

Keywords: Neutron diffraction, Tof-diffractometer, Strain scanning, Neutron mirror, Time-focusing detector

DOI: 10.1080/10238160108200173

Citation: Journal of Neutron Research, vol. 9, no. 2-4, pp. 423-429, 2001

Authors: Levy-Tubiana, R. | Molliex, L. | Lodini, A.

Article Type: Research Article

Abstract: Diffraction-based stress measurement techniques have been widely applied to the study of two-phase and composite materials [1,2]. Diffraction is particularly useful and that allows the strains (and hence stresses) to be measured independently in both phases of the material, which can give useful information on mechanical behavior. We analyze a bling in titanium reinforced by fibers of SiC: strains are measured, stresses of each phase and macrostresses are quantified.

Keywords: Neutron diffraction, Residual stresses, Ti–Sic composites, Titanium matrix composites

DOI: 10.1080/10238160108200174

Citation: Journal of Neutron Research, vol. 9, no. 2-4, pp. 431-434, 2001

Authors: Pyzalla, A. | Jacques, A. | Feiereisen, J.-P. | Buslaps, T. | D’Almeida, T. | Liss, K.-D.

Article Type: Research Article

Abstract: First results on the investigation of the tensile load stress-elastic strain response of an AlSi-metal matrix composites are presented. Measurements were performed at room temperature and in-situ at elevated temperature using white high-energy synchrotron radiation. The experiments show the evolution of the lattice plane dependent microstrains in the aluminium matrix and the silicon particles.

Keywords: White high energy synchrotron radiation, Metal matrix composite, Tensile deformation, Elevated temperature

DOI: 10.1080/10238160108200175

Citation: Journal of Neutron Research, vol. 9, no. 2-4, pp. 435-442, 2001

Authors: Millet, P. | Girardin, E. | Braham, C. | Lodini, A.

Article Type: Research Article

Abstract: During clinical use of an implant, the mechanical stresses are added to pre-existing residual stresses. The magnitude of these stresses affects the hydroxyapatite coating’s performance. We intended to study in this work, by neutron diffraction and conventional X-ray diffraction methods, the macrostresses induced by a plasma-spraying process in the coating and at the interface. Neutron diffraction is a suitable technique to study the strain distribution in a bulk material. X-ray diffraction has been used to determine residual stress in the hydroxyapatite coating. Using neutron diffraction method, we calculate the stress on the titanium alloy but see no real difference between …the stress on the coated and the non-coated samples. With X-ray diffraction method, it appears that the stress level is compressive on every sample. The major interest of neutron diffraction method is that measurements can be done on a thick coating, in a non-destructive way with the disadvantage of a large gauge volume that we had to use. Polishing is necessary for measurements inside the material when using X-ray method. This destructive method may alter the stress field of the deposit. Show more

Keywords: Implant, Hydoxyapatite coatings, Stress, Strain, Neutron diffraction, X-ray diffraction

DOI: 10.1080/10238160108200176

Citation: Journal of Neutron Research, vol. 9, no. 2-4, pp. 443-448, 2001

Authors: Sprauel, J.M.

Article Type: Research Article

Abstract: Neutron stress evaluation is reliable in normal condition where the neutron probe is entirely immersed in the sample. However, near surface measurements are difficult to analyse, due to great parasitic peak shifts which are obtained in such condition. To correct these systematic errors, a numerical modelling of a whole two-axis neutron spectrometer has been developed. The simulation program computes the distribution of intensity and wavelength across the incident beam. The precise shape and size of the probe volume is also calculated. A theoretical diffraction peak is finally built through a modified Monte Carlo simulation method. The whole simulation program allows …thus to predict and correct all parasitic shifts of the diffraction peak. To check the limits of the method, the procedure has been applied to the evaluation of the residual stresses induced by surface treatments, such as nitriding and shot peening. Show more

Keywords: Neutron spectrometer, Stress evaluation, Monte-Carlo simulation, Neutron diffraction

DOI: 10.1080/10238160108200177

Citation: Journal of Neutron Research, vol. 9, no. 2-4, pp. 449-457, 2001

Authors: Albertini, G. | Ceretti, M. | Caglioti, G. | Fiori, F. | Monzani, R. | Viviani, L.

Article Type: Research Article

Abstract: The residual stress field in shrink-fit disc-ring systems was investigated in the framework of a general research, the final goal of which is to establish optimisation criteria for the joining procedure in the AA6082 aluminium alloy. In particular, two different procedures were considered: the traditional thermoelastic and an innovative thermoelastoplastic coupling. The two processes were simulated by finite element calculations, which were optimised by comparison with existing analytic models. Neutron diffraction experiments were carried out on samples obtained by the two procedures. The comparison between the theoretical and experimental results showed a satisfactory agreement. Small differences found were ascribed to …already existing residual stresses, which were actually measured in uncoupled samples. Show more

Keywords: A1 alloy 6082, Shrink-fit, Residual stresses, Finite element, Neutron diffraction

DOI: 10.1080/10238160108200178

Citation: Journal of Neutron Research, vol. 9, no. 2-4, pp. 459-467, 2001

Authors: Daymond, M.R. | Johnson, M.W.

Article Type: Research Article

Abstract: A method for the calculation of a stress free lattice parameter from the analysis of diffraction data from stressed material is discussed, utilising the elastic anisotropy of the material. The technique is demonstrated using the data obtained during a uni-axial tension test on austenitic steel. The uncertainty in the calculated lattice parameter for various choices of a number of diffraction peaks and when different stress levels are available for the calculation is considered. It is shown that when all the data is within the elastic regime, an accurate evaluation of the reference lattice parameter can be made. When some data …is in the plastic regime, a more limited evaluation is possible. Show more

Keywords: Elastic anisotropy, Stress free lattice parameter, Crystallite, Diffraction peak

DOI: 10.1080/10238160108200179

Citation: Journal of Neutron Research, vol. 9, no. 2-4, pp. 469-479, 2001

Authors: Carrerot, H. | Desvaux, S. | Gualandri, J. | Lamare, A.

Article Type: Research Article

Abstract: SNFA has decided to develop the Barkhausen noise technique in order to determine the state of stresses and the microstructural changes in the contact zones of the bearing raceways and rolling elements. Based on its know-how, its practical experience on site of the X-ray diffraction method and the non-destructive techniques (Micrography, Fluorescent Penetrant Inspection, Magnetic Particle Inspection, Nital Etch and Eddy Current), SNFA is today in a position to officially state the efficiency of the Barkhausen noise technique to estimate the state of stresses in the bearings. A specifically developed software allows us to estimate the residual stress profiles on …the following bearing contact zones: raceways after grinding; raceways after prestressing; and raceways after operation on an engine. Show more

Keywords: Barkhausen noise, Residual stresses, X-ray diffraction, Non destructive testing

DOI: 10.1080/10238160108200180

Citation: Journal of Neutron Research, vol. 9, no. 2-4, pp. 481-488, 2001

Authors: Grosse, M. | Stuhr, U. | Ceretti, M. | Köszegi, L.

Article Type: Research Article

Abstract: The radial strain in an ICE railway wheel hoop was scanned over the cross section perpendicular to the hoop direction. Only in the middle part of the hoop cross section compressive strain were found. In a band between a distance of 5 – 12 mm from the tread relative large tensile strain was estimated. In other regions only low strains were obtained. A comparison of the estimated strain distribution with the fracture surface of a broken hoop with comparable wear shows correlation between the strain distribution and the fracture appearance.

Keywords: Strain scanning, Railway wheels, Radial strain, Estimated strain

DOI: 10.1080/10238160108200181

Citation: Journal of Neutron Research, vol. 9, no. 2-4, pp. 489-493, 2001

Authors: Wanner, Alexander | Dunand, David C.

Article Type: Research Article

Abstract: The availability of high-energy X-rays from 3rd-generation synchrotron sources offers new approaches to study internal stresses in the bulk of crystalline materials. A method with a wide application potential is the transmission technique introduced by Daymond and Withers, which however has so far been limited to fine-grained materials. In the present work, the reasons for the currently existing limitations are discussed and a viable strategy to extend the technique to samples with coarser grain sizes is proposed.

Keywords: Internal stress measurement, X-ray diffraction, Monochromatic high-energy X-rays, Probe volume, Grain size

DOI: 10.1080/10238160108200182

Citation: Journal of Neutron Research, vol. 9, no. 2-4, pp. 495-501, 2001