Foi construído um arranjo experimental para estudar o comportamento dos jatos evaporativos. Um injetor foi projetado para controlar e manter constantes a pressão e temperatura de reservatório durante a injeção. Um bocal cônico convergente de seção reta com diâmetro de saída de 0,30 mm e ângulo entre sua geratriz e seu eixo simetria igual à 10º forma o elemento principal do injetor. O jato é descarregado em uma câmara de baixa pressão de dimensões suficientemente grandes para manter a pressão constante durante o curto período de ensaio, igual à 1 s. Quando injetado, o líquido sofre uma repentina queda de pressão ocasionando sua evaporação. Os fluidos utilizados são os combustíveis querosene e óleo diesel, e a substância n-dodecano, os quais se caracterizam pela possibilidade de uma evaporação completa, de forma adiabática. Utilizou-se o método \"schlieren\" para a visualização do escoamento. A análise dos jatos é feita de forma qualitativa através dos registros fotográficos. Foram observados os seguintes tipos de jato: (1) contínuo, (2) pulverizante e (3) evaporação na superfície. O primeiro jato não implica em imediata mudança de fase tornando o jato de líquido emergente intacto. Com o aumento da temperatura de injeção, existe o espalhamento e a evaporação do jato, formando o segundo tipo de jato, onde é possível visualizar o campo do gradiente de densidade do escoamento e a formação de ondas de evaporação e de choque que pode ocorrer a uma distância proporcional a vários diâmetros à jusante. Em jatos com evaporação completa, foram constadas a formação de ondas de choque tanto de formas elipsóide como de esferóide para elevadas temperaturas. As fotografias digitais são submetidas à filtragem e processamento matemático para melhor destacar tais fenômenos do escoamento. / An experimental apparatus has been built to study the behaviour of flashing jets. An injector was designed to control and maintain the jet pressure and temperature at constant values during the injection process. A conical convergent nozzle whose main dimensions are 0,30 mm of exit diameter, 8 mm long, and a convergence half-angle of 10º is the central component of the injection system. The jet is discharged into a low-pressure chamber large enough to keep the reservoir pressure constant during the short test period of about 1 s. As the testing liquid expands in the nozzle it undergoes a sudden pressure drop causing its evaporation. The fluids are usual fuels, such as kerosene and diesel oil, and the substance ndodecane, which are distinguishable by the possibility of a complete evaporation in an isoentropic expansion process. The photographic method \"schlieren\" is used for flow visualisation. A qualitative analysis is made of the photographic documentation of the images obtained using a CCD camera. The images can be grouped into three categories of jets: (1) continuous, (2) shattering, and (3) with surface evaporation. The first regime has an undisturbed a liquid column, which remains more or less intact during the injection process. In the second type, the existing liquid jet is shattered by vapour nucleation and, in some cases, shock waves are clearly visible. It happens at higher temperature than the preceding evaporation mode. Finally, in special situations, the jet undergoes an evaporation at its surface and the two-phase mixture expands at a high speed followed by a shock wave before the mixture attains the pressure reservoir.

Devido à importância de cavidades de vapor em meios líquidos, para áreas como transferência de calor e de escoamento em tubos (nos quais elas podem causar sérios danos), o processo de formação e colapso de bolhas tem sido largamente estudado, e boa parte do que ocorre em escala micro já foi reportado. Nos últimos anos, novos estudos no campo têm demonstrado que cavidades de diâmetro não desprezível (chegando a dezenas de centímetros), podem ser geradas em condições controladas. O mecanismo dos experimentos de formação dessas cavidades se aproveita do fato de que substâncias puras (ou quase puras) podem ser mantidas como líquido em temperaturas bem acima das de mudança de fase, e a transição de fase propriamente dita necessita de um mecanismo facilitador ou um ponto de iniciação, de modo que um estado superaquecido pode ser mantido por muito tempo até que essa condição seja alcançada, gerando uma mudança de fase extremamente rápida, e muitas vezes explosiva. As chamadas macro cavidades, geradas por esse processo, possuem uma dinâmica geral de formação e colapso bem semelhante as que ocorrem em escala micro, porém uma série de outros aspectos podem ser observadas nas mesmas, tais como formação de jato central e de película de líquido ascendente junto a parede. Esses aspectos específicos do escoamento, embora descritos em trabalhos anteriores, ainda não foram completamente compreendidos, e se mostram como um desafio na reprodução dos experimentos e na quantificação de força útil gerada. Dessa forma, este estudo se propõem ao melhor entendimento desses detalhes específicos acerca das macro cavidades. Através de filmagens em alta velocidade dos experimentos, e da análise dos dados gerados por essas filmagens, foi realizada uma análise dos mecanismos envolvidos na formação dos jatos centrais e dos filmes ascendentes, comparando a forma como esses efeitos se dão para o caso de macro cavidades com o relatado na bibliografia para casos semelhantes. A fim de facilitar a compreensão da física por trás dos mecanismos de amplificação de ondas, um modelo simplificado da instabilidade de Rayleigh-Taylor aplicado ao fenômeno também foi abordado. / Because of the importance of vapor cavities in liquid, for areas such as heat transfer and pipe flow (in which they can cause serious damage), the process of formation and collapse of bubble has been largely studied, and much of what occurs on a micro scale has already been reported. In recent years new studies in the field have shown that cavities of non-negligible diameter (up to tens of centimeters) can be generated under controlled conditions. The mechanism for the experiments of cavity formation takes advantage of the fact that pure (or near pure) substances can be kept as liquid at temperatures well above the phase change, and the phase transition itself requires a facilitating mechanism or a starting point, such that an overheated state can be maintained for a long time until this condition is reached, generating an extremely rapid, and often explosive, phase change. The so-called macro cavities, generated by this process, have a general dynamics of formation and collapse very similar to those that occur in micro scale, but a number of other aspects can be observed in them, such as formation of central jet and a liquid climbing film close to the wall. These specific aspects of the flow, although described in previous work, have not yet been fully understood, and are shown as a challenge in the reproduction of experiments and in the quantification of useful force generated. Thus, this study proposes to better understand these specific details about the macro cavities. Through high speed filming of the experiments and analysis of the data generated by these films, an analysis was made of the mechanisms involved in the formation of the central jets and the climbing films, comparing the way these events occur in the case of macro cavities, with the reported in the bibliography for similar cases. In order to facilitate the understanding of the physics behind the mechanisms of wave amplification, a simplified model of Rayleigh-Taylor instability applied to the phenomenon was also addressed.

Foi construído um arranjo experimental para estudar o comportamento dos jatos evaporativos. Um injetor foi projetado para controlar e manter constantes a pressão e temperatura de reservatório durante a injeção. Um bocal cônico convergente de seção reta com diâmetro de saída de 0,30 mm e ângulo entre sua geratriz e seu eixo simetria igual à 10º forma o elemento principal do injetor. O jato é descarregado em uma câmara de baixa pressão de dimensões suficientemente grandes para manter a pressão constante durante o curto período de ensaio, igual à 1 s. Quando injetado, o líquido sofre uma repentina queda de pressão ocasionando sua evaporação. Os fluidos utilizados são os combustíveis querosene e óleo diesel, e a substância n-dodecano, os quais se caracterizam pela possibilidade de uma evaporação completa, de forma adiabática. Utilizou-se o método \"schlieren\" para a visualização do escoamento. A análise dos jatos é feita de forma qualitativa através dos registros fotográficos. Foram observados os seguintes tipos de jato: (1) contínuo, (2) pulverizante e (3) evaporação na superfície. O primeiro jato não implica em imediata mudança de fase tornando o jato de líquido emergente intacto. Com o aumento da temperatura de injeção, existe o espalhamento e a evaporação do jato, formando o segundo tipo de jato, onde é possível visualizar o campo do gradiente de densidade do escoamento e a formação de ondas de evaporação e de choque que pode ocorrer a uma distância proporcional a vários diâmetros à jusante. Em jatos com evaporação completa, foram constadas a formação de ondas de choque tanto de formas elipsóide como de esferóide para elevadas temperaturas. As fotografias digitais são submetidas à filtragem e processamento matemático para melhor destacar tais fenômenos do escoamento. / An experimental apparatus has been built to study the behaviour of flashing jets. An injector was designed to control and maintain the jet pressure and temperature at constant values during the injection process. A conical convergent nozzle whose main dimensions are 0,30 mm of exit diameter, 8 mm long, and a convergence half-angle of 10º is the central component of the injection system. The jet is discharged into a low-pressure chamber large enough to keep the reservoir pressure constant during the short test period of about 1 s. As the testing liquid expands in the nozzle it undergoes a sudden pressure drop causing its evaporation. The fluids are usual fuels, such as kerosene and diesel oil, and the substance ndodecane, which are distinguishable by the possibility of a complete evaporation in an isoentropic expansion process. The photographic method \"schlieren\" is used for flow visualisation. A qualitative analysis is made of the photographic documentation of the images obtained using a CCD camera. The images can be grouped into three categories of jets: (1) continuous, (2) shattering, and (3) with surface evaporation. The first regime has an undisturbed a liquid column, which remains more or less intact during the injection process. In the second type, the existing liquid jet is shattered by vapour nucleation and, in some cases, shock waves are clearly visible. It happens at higher temperature than the preceding evaporation mode. Finally, in special situations, the jet undergoes an evaporation at its surface and the two-phase mixture expands at a high speed followed by a shock wave before the mixture attains the pressure reservoir.

O fenômeno da nucleação é um processo intrinsecamente irreversível. A Teoria Entrópica da Nucleação (TEN) aborda-o analisando um processo reversível equivalente no qual há liberação de calor latente (variação da entalpia), concomitante a um rearranjo estrutural descrito pela variação da entropia antes e depois de certa quantidade de material ter nucleado. Para visualizar a dinâmica e facilitar a análise foi escolhido um processo isobárico. O diagrama de Mollier modificado para evidenciar a região metaestável ajudou a desenvolver uma expressão para o cálculo do tamanho do núcleo crítico, mediante a teoria da flutuação de Landau. Para analisar o sistema na região metaestável, obteve-se a função entropia, S(H,P0), em que aspectos físicos e geométricos (como o princípio de estabilidade termodinâmica) foram determinantes. Cálculos do núcleo crítico em relação à temperatura mostraram concordância qualitativa com o trabalho de Dillmann-Meier. Porém, entende-se que a função do núcleo crítico está incompleta. Para lidar com aglomerados e núcleos em uma abordagem termodinâmica, um ensemble a pressão constante é o mais apropriado, cuja variável conjugada é o volume. Com base em uma teoria das flutuações isotérmicas em um fluido ideal (Koper-Reiss), desenvolveu-se a teoria das flutuações não-isotérmicas (Mokross), aplicável a um fluido não-ideal metaestável mantido a pressão e temperatura constantes. Os parâmetros termodinâmicos do elemento de volume que flutua mudam e diferem daqueles do banho, e evolvem acordando com a equação de estado S=S(H,P). / The phenomenon of nucleation is an intrinsically irreversible process. The nucleation is explored by the Entropic Nucleation Theory (ENT), in which, the irreversible process is replaced by an equivalent one, although now, the process is reversible in which there is a change in the enthalpy, and also an structural rearrangement coded in the change of de entropy. To study the dynamics and perform the analysis an isobaric process was chosen. The metastable region was used to develop an expression for the calculation of size of the critical nucleus, having in mind the Landau´s fluctuation theory. This region was obtained with the help of the modified Mollier diagram. The physical and geometric features of the system were crucial to obtain the entropy function, S(H,P0), used to analyze the metastable region. Calculations of the critical nucleus, with respect to the temperature, were in qualitative agreement with Dillmann-Meier work. Although, the function for the critical nucleus is incomplete. To handle with clusters and nucleus in a thermodynamic framework, a constant pressure assemble is preferable having the volume as the conjugated variable. With the help of the isothermal fluctuation theory, in an ideal fluid (Koper-Reiss), the non-isothermal fluctuation theory (Mokross) was developed, and used to study a non-ideal metastable fluid kept at constant pressure and temperature. The thermodynamics parameters of the fluctuating volume element change, differing from those of the bath, and the state equation, S=S(H,P) gives its evolution.

Devido à importância de cavidades de vapor em meios líquidos, para áreas como transferência de calor e de escoamento em tubos (nos quais elas podem causar sérios danos), o processo de formação e colapso de bolhas tem sido largamente estudado, e boa parte do que ocorre em escala micro já foi reportado. Nos últimos anos, novos estudos no campo têm demonstrado que cavidades de diâmetro não desprezível (chegando a dezenas de centímetros), podem ser geradas em condições controladas. O mecanismo dos experimentos de formação dessas cavidades se aproveita do fato de que substâncias puras (ou quase puras) podem ser mantidas como líquido em temperaturas bem acima das de mudança de fase, e a transição de fase propriamente dita necessita de um mecanismo facilitador ou um ponto de iniciação, de modo que um estado superaquecido pode ser mantido por muito tempo até que essa condição seja alcançada, gerando uma mudança de fase extremamente rápida, e muitas vezes explosiva. As chamadas macro cavidades, geradas por esse processo, possuem uma dinâmica geral de formação e colapso bem semelhante as que ocorrem em escala micro, porém uma série de outros aspectos podem ser observadas nas mesmas, tais como formação de jato central e de película de líquido ascendente junto a parede. Esses aspectos específicos do escoamento, embora descritos em trabalhos anteriores, ainda não foram completamente compreendidos, e se mostram como um desafio na reprodução dos experimentos e na quantificação de força útil gerada. Dessa forma, este estudo se propõem ao melhor entendimento desses detalhes específicos acerca das macro cavidades. Através de filmagens em alta velocidade dos experimentos, e da análise dos dados gerados por essas filmagens, foi realizada uma análise dos mecanismos envolvidos na formação dos jatos centrais e dos filmes ascendentes, comparando a forma como esses efeitos se dão para o caso de macro cavidades com o relatado na bibliografia para casos semelhantes. A fim de facilitar a compreensão da física por trás dos mecanismos de amplificação de ondas, um modelo simplificado da instabilidade de Rayleigh-Taylor aplicado ao fenômeno também foi abordado. / Because of the importance of vapor cavities in liquid, for areas such as heat transfer and pipe flow (in which they can cause serious damage), the process of formation and collapse of bubble has been largely studied, and much of what occurs on a micro scale has already been reported. In recent years new studies in the field have shown that cavities of non-negligible diameter (up to tens of centimeters) can be generated under controlled conditions. The mechanism for the experiments of cavity formation takes advantage of the fact that pure (or near pure) substances can be kept as liquid at temperatures well above the phase change, and the phase transition itself requires a facilitating mechanism or a starting point, such that an overheated state can be maintained for a long time until this condition is reached, generating an extremely rapid, and often explosive, phase change. The so-called macro cavities, generated by this process, have a general dynamics of formation and collapse very similar to those that occur in micro scale, but a number of other aspects can be observed in them, such as formation of central jet and a liquid climbing film close to the wall. These specific aspects of the flow, although described in previous work, have not yet been fully understood, and are shown as a challenge in the reproduction of experiments and in the quantification of useful force generated. Thus, this study proposes to better understand these specific details about the macro cavities. Through high speed filming of the experiments and analysis of the data generated by these films, an analysis was made of the mechanisms involved in the formation of the central jets and the climbing films, comparing the way these events occur in the case of macro cavities, with the reported in the bibliography for similar cases. In order to facilitate the understanding of the physics behind the mechanisms of wave amplification, a simplified model of Rayleigh-Taylor instability applied to the phenomenon was also addressed.

First-principles calculations such as density functional theory (DFT) employ numerical approaches to solve the Schrodinger equation of a system. Standard functionals employed to determine the cohesive system energy, specifically the local density and generalized gradient approximations (LDA and GGA), underestimate the correlation of 5f electrons to their ions in AO₂ systems (A=U/Pu/Np). The standard correction, the "Hubbard +U," causes the multidimensional energy surface to develop a large number of local minima which do not correspond to the ground state (global minimum). Because all useful energy values derived from DFT calculations depend on small differences between relatively large cohesive energies, comparing systems wherein one or more of the samples are not in the ground state has the potential to introduce large errors. This work presents an analysis of the fundamental issues of metastable states in both pure and binary AO₂ systems, investigates novel methods of handling them, and describes why current literature approaches which appear to work well for the pure compounds are not well-suited for systems containing multiple actinide species.

This thesis is an investigation of surface morphology and electronic structure of self-assembled monolayers (SAMs) and solid water films deposited on these SAMs using metastable impact electron spectroscopy (MIES) and infrared reflection-absorption spectroscopy (IRRAS). MIES uses electronically excited slow helium atoms which interact exclusively with the outermost surface layer. The results suggested that in the SAMs containing an odd number of carbon atoms the molecular orbitals localized on the terminal methyl groups are more exposed at the surface compared to those with an even number of carbon atoms. It was also established that solid water films are more uniform on a SAM substrate containing an odd number of carbon atoms. Thermal transformation of amorphous solid water to polycrystalline ice was also observed. MIES suggested that the molecular orbital of water attributed to the lone pair on the oxygen atom became less accessible at the surface upon the transformation.

Zeeman deceleration is an experimental technique which allows for the manipulation of open-shell atoms and molecules in a supersonic beam thus producing mK-cold, velocity-tunable beams of particles in selected quantum states. The method relies on the Zeeman interaction between paramagnetic particles and time-varying, inhomogeneous magnetic fields generated by pulsing high currents through an array of solenoid coils. This thesis describes the construction and implementation of a supersonic beam setup including a 12-stage Zeeman decelerator. The Zeeman decelerator follows an original design that makes it possible to replace individual deceleration coils. Using ground-state hydrogen atoms as a test system, it is shown that the transverse acceptance in a Zeeman decelerator can be significantly increased by generating a rather low, temporally varying quadrupole field in one of the solenoid coils. An electron-impact source was constructed and optimised enabling, for the first time, the Zeeman deceleration of metastable helium atoms in the 23S1 state, with an up to 40 % decrease in the kinetic energy of the beam. It is shown that the pulse duration for electron-impact excitation needs to be matched to the acceptance of the decelerator in order to attain a good contrast between the decelerated and undecelerated parts of the beam. Experimental results are rigorously analysed and interpreted using three-dimensional numerical particle trajectory simulations. A phase-space model provides, for the first time, a means to estimate the six-dimensional phase-space acceptance in a Zeeman decelerator and to find optimum parameter sets for improved Zeeman deceleration schemes. The approach also reveals a hitherto unconsidered velocity dependence of the phase stability which is ascribed mainly to the rise and fall times of the current pulses that generate the magnetic fields inside the deceleration coils. In the future, it is planned to combine the Zeeman decelerator with a source of cold atomic and molecular ions to study chemical collisions at low temperatures. A hybrid magnetic guide consisting of permanent magnet assemblies (Halbach arrays) in hexapole configuration and a set of current-carrying wires is proposed and simulated as an interface between these setups. The design promises very efficient velocity selection, a high degree of quantum-state selection and a nearly complete removal of residual carrier gas. Prospects for using magnetic hexapole focusing in front of the Zeeman decelerator are discussed. The work represents a major step towards the study and control of chemical reactivity of paramagnetic species in the low-temperature regime and it will help in the testing of fundamental chemical reaction theories.

Dans ce travail, basé sur une approche semi empirique de conception d’alliages de titane à propriétés mécaniques contrôlées, un alliage modèle binaire Ti-12Mo (% massique) et des alliages ternaires sur la base du système Ti-Mo ont été élaborés, combinant des effets TRIP et TWIP lors de la déformation. (TRIP – Transformation Induced Plasticity : plasticité induite par transformation ; TWIP – Twinning Induced Plasticity : plasticité induite par maclage).Les résultats des essais mécaniques montrent que ces alliages présentent une haute résistance mécanique (1000-1200 MPa), une grande plasticité (entre 0,3 et 0,4) et un écrouissage amélioré grâce aux effets simultanés TRIP/TWIP. Différentes techniques de caractérisation telles que la diffraction de rayons X conventionnelle (XRD), la diffraction in-situ sur Synchrotron (SXRD), la diffraction d’électrons rétro-diffusés (EBSD), les mesures de résistivité électrique (ERM), la microscopie électronique en transmission (TEM) et les mesures et traitements automatiques des orientations cristallographiques associées (ACOM/TEM), ont été mis en œuvre pour étudier les mécanismes de déformation, les transformations de phases et l’évolution microstructurale.Différents mécanismes de déformation, tels que le maclage mécanique {332}<113> et la transformation martensitique induite sous contrainte α˝ ont été identifiés à l’issue des essais mécaniques, permettant d’expliquer l’excellente combinaison de propriétés mécaniques obtenue. L’optimisation microstructurale de ces alliages a été conduite à partir de recuits basses températures dans le domaine de précipitation de la phase ω avec pour objectif d’améliorer les propriétés mécaniques afin de contrôler la formation de la phase ω sans modifier de manière excessive la composition chimique de la matrice β, et conserver les effets combinés TRIP/TWIP. / In this work, based on combination of the ‘d-electron alloy design method’ and controlling of electron/atom ratio (e/a), a model of binary Ti-12Mo (wt. %) and ternary Ti-Mo based alloys were designed, induced combined TRIP and TWIP effects (TRIP for Transformation Induced Plasticity and TWIP for Twinning Induced Plasticity). The tensile results show that so-designed alloys exhibit true stress-strain values at uniform plastic deformation, of about 1000-1200MPa and between 0.3 and 0.4 of strain, with a large strain-hardening rate. Several characterization techniques, such as conventional X-ray diffraction (XRD), In-situ Synchrotron X-ray diffraction (SXRD), electron backscatter diffraction (EBSD), electrical resistivity measurements (ERM), transmission electron microscopy (TEM) and automatic crystal orientation measurements (ACOM) TEM, were carried out to to investigate the deformation mechanisms and microstructure evolution sequence. Various deformation mechanisms, i.e. {332}<113> mechanical twinning, deformation induced ω phase and stress-induced α’’ martensite, were identified after mechanical testing, resulting in a combination of high strength, large ductility and improved strain-hardening rate. Furthermore, low temperature aging (LTA) treatments were performed on the Ti-12Mo alloy to improve the mechanical property through controlling the ω phase transformation without excessive modification of β matrix chemical composition, keeping the possibility for combined TRIP and TWIP effects to occur. The influence of LTA treatment on the mechanical behavior and microstructural evolution of Ti-12Mo alloy was discussed in detail.

Ce travail a porté sur l'étude des phases métastables de l'alliage à mémoire de forme CuAlBe sous différents types de sollicitations mécaniques et thermiques par diffraction des neutrons. Il a permis de définir un protocole expérimental de caractérisation des transformations des phases métastables caractéristiques de l'effet mémoire de forme et de la superélasticité. Après élaboration par filage à chaud suivi d'une trempe à l'eau, le matériau est entièrement austénitique β1. Sa microstructure est composée de grains de taille relativement importante, de l'ordre de 400 µm. Ce procédé de fabrication génère une texture cristallographique de type fibre partielle <001>. L'étude de la superélasticité lors d'un essai de traction à température ambiante a mis en évidence le comportement pseudoélastique de l'alliage. L'étude de l'évolution des microdéformations a permis de mettre en avant la forte hétérogénéité de comportement du plan (400). Le pic de diffraction de ce plan présente également un fort élargissement dû aux fautes d'empilements qui est directement à relier à la transformation de phase de l'austénite en martensite. La martensite β'1 de structure monoclinique 18R complexe a été affinée à l'aide d'un modèle de type 6M. Ce modèle permet de rendre compte au mieux de la faible périodicité des fautes d'empilement caractéristiques de cette phase métastable à notre échelle d'analyse caractéristique d'un volume de l'ordre du centimètre cube. Après déformation plastique, la texture cristallographique du matériau a fortement évoluée. Le laminage à froid fait disparaitre la fibre partielle <001>. Aux plus forts taux de déformation plastique par laminage à chaud, la fibre <111> apparait. Cette forte déformation affecte également l'orientation des lattes de martensite. D'autre part, les températures des transformations de phases ainsi que l'hystérésis sont modifiées. Cependant, la structure cristallographique de la martensite générée par déformation plastique est identique à celle obtenue par refroidissement pour notre échelle d'observation. L'étude du retour à l'équilibre des phases métastables après recuit à haute température suivi d'une trempe sur un échantillon déformé plastiquement a montré la disparition totale de la martensite et l'apparition des phases stables α et γ2 pour des températures de recuit entre 500°C et 600°C. Au-delà de 600°C, ces deux phases disparaissent au profit de la phase β. On observe alors un fort grossissement du grain. La texture cristallographique est de nouveau caractérisée par la fibre partielle <001>. / This work deals with the study of metastable phases of CuAlBe shape memory alloy under mechanical and thermal solicitations by neutron diffraction. It enables to define an experimental protocol of characterization of metastable phase transformation.The raw material is fully austenitic at room temperature. Its microstructure is composed by huge grain size, close to 400 µm. The crystallographic texture is characterized by a <001> partial fibber.The study of the superelasticity during a tensile test at room temperature demonstrated the pseudoelastic behaviour of this material. The evolution of microdeformations showed the heterogeneous behaviour, especially for the (400) plane in axial direction. The diffraction peak of this plane family also has an important increase of the width. This increase can be linked to the transformation of the austenite into martensite.The crystallographic structure of the monoclinic martensite β'1 has been refined using the 6M model. This model enables to report the relatively low periodicity of stacking faults characterizing the martensitic transformation.After plastic deformation, the crystallographic texture evolved. The <001> partial fibber disappears. For the larger deformation rates, the <111> fibber appears.This large deformation also affects the martensite variant orientation and modifies the temperature of phase transformation.The return into equilibrium of metastable phases after annealing treatments between 500°C and 600°C followed by a quenching at room temperature on a plastically deformed sample has shown the disappearance of martensite and the growth of α and γ2 stable phases. Beyond 600°C, the grains grow largely. The crystallographic texture is characterized by the <001> partial fibber.