Civitanova Marche, Italy
Civitanova Marche, Italy

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Rogante M.,Rogante Engineering Office | Mikula P.,Nuclear Physics Institute of Czech Republic | Vrana M.,Nuclear Physics Institute of Czech Republic
Key Engineering Materials | Year: 2011

The residual stress (RS) status induced in the substrate of coated materials by the coating process plays frequently a major role in lending the component's characteristics. RS assessment can give, thus, a substantial contribution in justifying different cases of failure or else bad performance of coated components due to e.g. the coating delamination or to other occurrences which are not simply interpretable via the conventional mechanical tests or microstructure analyses. The adoption of both neutron diffraction (ND) and X-ray diffraction (XRD) techniques has revealed its usefulness in assessing the RS values in proximity of the coating interface area, respectively, without any layer removal or hole drilling at the extreme surface. In this paper, some real cases of RS determination in coated materials by using these techniques and exploiting their complementarity are described. ND, in particular, is very suitable for crucial applications, where a much different stress situation than that assessed by XRD could be present at some depth below the surface. The results achieved can yield trends adoptable in monitoring of the coating features. © (2011) Trans Tech Publications. Switzerland.

Rogante M.,Rogante Engineering Office | Lebedev V.T.,RAS Petersburg Nuclear Physics Institute
Journal of Alloys and Compounds | Year: 2012

Udimet 520 and Udimet 720 samples submitted to different annealing temperatures and ageing times have been investigated by small angle neutron scattering (SANS), with the aim to study precipitates phases microstructural evolution and materials' behaviour. These materials are γ′ (Ni 3Al, Ti) precipitation hardened nickel-based superalloys possessing high strength, corrosion resistance and metallurgical stability. They are mainly adopted in high temperature environment, having found applications over a very wide range of temperature. Their importance has increased thanks to their good balance of mechanical properties and economic potential. Information on the thermal treatment effects has been obtained, in particular concerning precipitate size and volume fraction distributions. The results contribute to confirm SANS to a level of industrial applicability in the considered sectors. © 2011 Elsevier B.V. All rights reserved.

Heaton M.E.,Imperial College London | Rogante M.,Rogante Engineering Office | Len A.,Hungarian Academy of Sciences | Denieffe D.,Institute of Technology Carlow
Multidiscipline Modeling in Materials and Structures | Year: 2010

Purpose - The purpose of this paper is to determine the nano-sized characteristics of SU-8 polymer micro-electromechanical systems airflow metrology turbines samples. These microturbines were made to be the first using axial airflow for low air pressure response. This polymer may be affected during curing by UV and heat baking, as well as confined heat from laser ablation. Defects in the resin matrix may influence the material quality and hence the final turbine performance. Design/methodology/approach - Small angle neutron scattering investigations were performed using the instrumentation of the Budapest Research Reactor. Findings - The average sizes of the voids/cracks in the resin matrix of the turbines were determined and allowed the viability of making smaller even thinner rotor blades for higher spin and electrical output capability to be considered. Originality/value - The obtained results have advanced the industrial applicability of the adopted technique in the considered sector of polymer analysis. © Emerald Group Publishing Limited.

Rogante M.,Rogante Engineering Office | Martinat G.,SKF Corporation | Mikula P.,Nuclear Physics Institute of Czech Republic | Vrana M.,Nuclear Physics Institute of Czech Republic
Kovove Materialy | Year: 2013

100Cr6 chrome steel submitted to martensitic hardening and tempering is usually adopted for particular industrial applications such as bearings, rings and rollers. These parts are often subjected to dynamic stresses in different fields of engineering and, consequently, it is important to know the residual stresses involved, especially in correspondence of critical zones, particularly fatigue-stress and/or crack sensitive. In this paper, the residual stress investigation by neutron diffraction in a 100Cr6 chromium steel ring - before and after the introduction of a hub fixed by orbital rolling - is presented. The results supply information on the real residual stress status, showing its enhancement due to the installation of the hub and the successive rolling operation. The achieved data can support the manufacturing process in order to improve the life assessment of the considered component.

Rogante M.,Rogante Engineering Office | Rosta L.,Hungarian Academy of Sciences
Strojarstvo | Year: 2011

A forging process can lead to material's micro- and nano-structure evolution, as well as production of internal residual stresses (RS). Typical fine-grained microstructures are achieved after forging at different temperatures, which are usually investigated and interpreted via conventional tests and analyses including optical, scanning and transmission of electron microscopy. The outputs from these methods can present an important lack of data, regarding basic parameters that aid comprehend and eventually predict degradation, possible fracture and lifetime. These parameters are determinable on real samples and can be supplied by neutron-based non-destructive diagnostic methods, in particular small angle neutron scattering (SANS) for micro- and nano-scale characterisation and neutron diffraction (ND) to assess internal RS. In this paper, some examples related to forged components - in particular, made of AlSi12CuNiMg alloy - are reported, concerning investigations by neutron techniques. The result can be translated directly into optimization of performances, reliability, design of operating conditions and procedures, in order to achieve a better quality of forged products.

Rogante M.,Rogante Engineering Office | Mazzanti M.,Fiat Powertrain Technologies S.p.A. | Mikula P.,Nuclear Physics Institute of Czech Republic | Vrana M.,Nuclear Physics Institute of Czech Republic
Kovove Materialy | Year: 2012

The residual stresses (RS) induced in the substrate by case hardening treatment (HT) play a significant role in the behaviour of power train engineering components. In this paper, the results of RS investigation by neutron diffraction (ND) in 20NiCrMo2 steel car gear-shafts are presented. The RS were measured in correspondence of the critical region (notch) which is sensitive to fatigue-stress and/or crack, namely before/after a hardening treatment and after the successive finishing process. The achieved results can supply useful information on the effects of the various manufacturing processes on the RS status, better to evaluate the extent of distortion before and after the hardening treatment and to give a substantial support in the life assessment of the considered components. Furthermore, these results can yield parameters exploitable in monitoring of the hardening treatment characteristics, thereby confirming the relevance of thermal stresses induced by the same hardening treatment.

Rogante M.,Rogante Engineering Office | Kovacs I.,Hungarian Academy of Sciences | Rosta L.,Hungarian Academy of Sciences | Stortoni E.,University of Macerata | Szokefalvi-Nagy Z.,Hungarian Academy of Sciences
Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms | Year: 2015

Six rather different bronze archaeological artefacts discovered over time in the Tifernum Mataurense area (S. Angelo in Vado, Marche Region, Italy) did not fit by visual inspection to the findings collected in nearby archaeological sites and they differ from each other, too. The primary goal of this work was to obtain data from the elemental composition of using a fast non-destructive quantitative analytical method. To do that the external milli-beam particle induced X-ray emission spectroscopy (external milli-beam PIXE) was chosen. Taking into account that not any invasive actions as burnishing, scratching or chemical treatment were allowed and the surface of the objects was rather corroded or patinated, the results obtained can be considered to be rather informative, only. Even these informative results, however, are useful to set up a classification of the objects according to the chemical composition and provide complementary near-surface composition information to the bulk data expected from cold neutron PGAA analyses to be performed. © 2015 Elsevier B.V. All rights reserved.

Rogante M.,Rogante Engineering Office | Mikula P.,Nuclear Physics Institute of Czech Republic | Vrana M.,Nuclear Physics Institute of Czech Republic
Key Engineering Materials | Year: 2014

Thermal neutrons are very useful probe in a nondestructive determination of internal stress/strains, due to their high penetration into most materials. In comparison with conventional X-ray techniques, real bulk information on both macro- and micro-strains in materials can be obtained by neutron diffraction (ND) techniques. Knowledge of the spatial and directional distribution of internal residual stresses (RS) is increasingly considered fundamental to determine their influence on properties of engineering materials and a consequent material behaviour. As the assesment of stresses is always related to the stress free material state, an accurate evaluation of the unstressed lattice parameters (e.g., the interplanar distance), in order to determine RS by ND is one of the key tasks. It helps to avoid inacceptable errors in the course of the real material strain and stress evaluation. The availability of carefully measured zero-strain standards is also essential to confirm the absence of systematic instrumental effects determining the diffraction profile at a chosen scattering angle. In this paper, the state of the art of the main analytical and experimental procedures currently established or adoptable to determine these critical parameters, particularly regarding industrial applications, is presented. © (2014) Trans Tech Publications.

Rogante M.,Rogante Engineering Office | Rosta L.,Hungarian Academy of Sciences | Heaton M.E.,Imperial College London
Measurement Science and Technology | Year: 2013

Neutron beam techniques, among other non-destructive diagnostics, are particularly irreplaceable in the complete analysis of industrial materials and components when supplying fundamental information. In this paper, nanoscale small-angle neutron scattering analysis and prompt gamma activation analysis for the characterization of industrial polymers are considered. The basic theoretical aspects are briefly introduced and some applications are presented. The investigations of the SU-8 polymer in axial airflow microturbines - i.e. microelectromechanical systems - are presented foremost. Also presented are full and feasibility studies on polyurethanes, composites based on cross-linked polymers reinforced by carbon fibres and polymer cement concrete. The obtained results have provided a substantial contribution to the improvement of the considered materials, and indeed confirmed the industrial applicability of the adopted techniques in the analysis of polymers. © 2013 IOP Publishing Ltd.

Rogante M.,Rogante Engineering Office
International Journal of Energy, Environment and Economics | Year: 2012

Lifetime prolongation and safety are key issues in planning and management of Nuclear Power Plants (NPPs), as knowledge of materials' conditions and related ageing processes is necessary either to ensure high levels of dependability or to deal with severe natural and plant-centred events. Conventional investigations, nevertheless, can present a lack of information, thus the data obtained require to be complemented. Decommissioning is not only a mere activity of installation's conclusion, but also an important opportunity to get materials, parts and worked systems submitted for decades to degradation and ageing. In dismantling a NPP, so, new diagnostic activities and measures for the installation of new components can be suggested to enhance safety and reliability of NPPs. Neutron investigations have lately become a progressively more considerable probe across a wide range of disciplines and they can reveal important properties about materials. Neutrons are becoming ever more helpful in the non-destructive characterisation of industrial materials and components of nuclear/traditional interests: applications of neutron-based methods, moreover, are being developed in a range of new sectors [1, 2]. In this paper, the following neutron techniques are briefly described, which can be exploited in the NPP field: small angle neutron scattering (SANS) for the micro- and nano-structural characterization as well as the radiation damage assessment; neutron diffraction (ND) for the determination of internal and sub-surface residual stresses (RS); prompt gamma activation analysis (PGAA) for qualitative and quantitative analyses of the material's constitutive main and trace elements. Some applications are also described. The available results, together with those from comparisons between naturally aged, new (non-aged) components and reference basic materials, can permit investigating in a supplementary way NPPs parts, helping to increase safety levels and service life of nuclear installations, with remarkable positive impact by either environmental or economical point of view. © 2012 Nova Science Publishers, Inc.

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