ABSTRACT In the automotive sector, aluminum alloys have stood out for their attractive combination of strength-to-weight ratio, among other characteristics. The 5XXX series alloys mechanical properties are related to their composition and the manufacturing process used, gaining most of their mechanical strength through cold deformation processes. One of the requirements to optimize mechanical forming operations is the microstructure and texture control. In this study, AA 5052 and AA 5050C alloys, produced by Direct Chill (DC) casting and Twin Roll Caster (TRC), respectively, underwent mechanical characterization through tensile testing (with specimens extracted at 0, 45, and 90° from the rolling direction); and microstructural and texture characterization across the thickness of the sheets. Alumina (Al2O3) inclusions and intermetallic precipitates of Al3Fe were detected along the metallic matrix of both alloys, exhibiting components of copper (112)[ 1 11 ¯], brass {110}<112>, cube (001)[ 0 10 ¯], and Goss {110}<001> throughout the thickness. AA 5052 alloy showed higher planar and normal anisotropy values than AA 5050C alloy, as well as mechanical properties measured in uniaxial tension. sector strengthtoweight weight ratio characteristics XXX used processes control study 505 C DC (DC TRC, TRC , (TRC) respectively with 45 90 direction direction) sheets Al2O3 AlO Al O (Al2O3 AlFe Fe 112 (112) ¯, ¯ ¯] 110<112>, 110112 110 <112>, {110}<112> 001 (001) 110<001> 110001 <001> {110}<001 tension 50 (TRC 4 9 Al2O (Al2O (112 110<112> 11011 <112> {110}<112 00 (001 110<001 11000 <001 {110}<00 5 (11 110<112 1101 <112 {110}<11 (00 110<00 1100 <00 {110}<0 (1 110<11 <11 {110}<1 (0 110<0 <0 {110}< ( 110<1 <1 110< < {110} {110 {11 {1 {

RESUMO No setor automotivo as ligas de alumínio têm se destacado por sua atraente combinação entre resistência/peso, entre outras características. As ligas da série 5XXX tem seu ganho de resistência mecânica através de processos de deformação a frio, e as propriedades mecânicas das ligas de alumínio estão diretamente relacionadas à sua composição e ao processo de fabricação utilizado em sua manufatura. Um dos requisitos para otimizar as operações de conformação mecânica é o controle da microestrutura e textura. Neste trabalho, as ligas AA 5052 e AA 5050C, produzidas por Fundição Direta (Direct Chill – DC), e Fundição Contínua de Chapas (Twin Roll Caster – TRC), respectivamente, passaram por caracterização mecânica via ensaio de tração (com corpos de provas extraídos a 0, 45 e 90° da direção de laminação) e caracterização estrutural e textura ao longo da espessura de chapas. Foram detectadas inclusões de alumina (Al2O3) e precipitados intermetálicos de Al3Fe juntos à matriz metálica e ambas as ligas apresentam as componentes cobre (112)[ 1 11 ¯], latão (“Brass”) {110}<112>, cubo (001)[ 0 10 ¯] e Goss {110}<001>, ao longo da espessura. A liga AA 5052 apresentou valores de coeficiente de anisotropia planar e normal superiores aos da liga AA 5050C, como também as propriedades mecânicas medidas em tração uniaxial. resistênciapeso peso resistência/peso características XXX frio manufatura trabalho 505 5050C C Direct DC, DC , DC) Twin TRC, TRC TRC) respectivamente com 4 90 laminação chapas Al2O3 AlO Al O (Al2O3 AlFe Fe 112 (112) ¯, ¯ Brass (“Brass” 110<112>, 110112 110 <112>, {110}<112> 001 (001) 110<001>, 110001 <001>, {110}<001> uniaxial 50 9 Al2O (Al2O (112 (“Brass 110<112> 11011 <112> {110}<112 00 (001 110<001> 11000 <001> {110}<001 5 (11 110<112 1101 <112 {110}<11 (00 110<001 1100 <001 {110}<00 (1 110<11 <11 {110}<1 (0 110<00 <00 {110}<0 ( 110<1 <1 {110}< 110<0 <0 110< < {110} {110 {11 {1 {

ABSTRACT During production and heat treatments of aluminum alloys, numerous second phase particles form, which maximizes their mechanical properties. This work aimed to perform a correlation between Vickers hardness and X-ray diffraction results, when 7475-T7351 aluminum alloy processed by the cross rolling is subjected to annealing heat treatments (AHT) at 500 °C for different soaking times (15, 30 and 60 minutes) and for a soaking time of 15 minutes at different temperatures (200, 300 and 400 °C). The influence of the AHT (500 °C / 15 minutes) on the microstructure, via scanning and transmission electron microscopy, and tensile tests properties was also investigated. The results show evidence that the Vickers hardness decreased for AHT performed at 200 and 300 °C / 15 minutes and increase for greater temperatures and times. This behavior is probably due to modifications in the constituent/dispersoid particles and aluminum matrix observed from the X-ray analysis. Partial recrystallization and a coarsening of the precipitates was observed after the AHT at 500 °C / 60 minutes, whose brought harmful effects on the tensile mechanical properties.

ABSTRACT Samples of the Al 7075 naturally and artificially aged were processed by conventional and asymmetrical rolling with 5% of thickness reduction. The rolling processes were evaluated under room temperature and under warm condition (130°C). Mechanical properties were evaluated by uniaxial tensile and Vickers microhardness tests. Microstructure evolutions were followed by optical microscopy analysis. Naturally aged samples showed better yield strengthening under warm processing. Greater ultimate stress and ductility under room temperature processing was also noticed in naturally aged specimens. Artificially aged samples showed better mechanical properties under room temperature, softening under warm processing due to grain recovery process. Microhardness tests showed expected results for both rolling types, especially on asymmetrical rolling with the higher predictions were observed. Micrographs have shown no expressive grain changes or refinement although its flattening was observed. Precipitates were analyzed by EDS/SEM revealing the presence of MgZn2 and CuMgAl along the matrix that provides plastic strengthening.

The API 5L X70 steel is used in high-pressure gas transmission pipelines. Because of this, knowledge of presence of residual stress and their magnitude is important to assess the material integrity in service. For the pipeline manufacturing, tubes need to be curved which is often made using the hot induction bending process. This process can introduce different residual stress depending of tube position. For this research, in order to evaluate the residual stress, was used an API 5L X70 tube that was previously curved by hot induction process. Samples were taken from the extrados, intrados, neutral line and straight section of the curved tube. Residual stresses were studied by two conventional methods: X-Ray Diffraction (XRD) and Hole-Drilling, which are destructive and non-destructive methods, respectively, in order to assess their qualitative responses. Each of these methods presents particular methodologies in sample preparation and material analysis, but also they differ in factors such time consumption and cost of the analysis. The qualitative responses obtained by the two different methods were comparable and satisfactory and pointed out the existence of a compressive residual stress state in steel pipe.

Abstract The crystallographic texture developed during cold rolling and subsequent annealing of interstitial free sheet steels aims to increase conformability. For this, it is necessary to obtain partial α-fiber and continuous and homogeneous γ-fiber texture components. In this work, the influence of symmetric (SR) and asymmetric (AR) cold rolling on crystallographic texture and mechanical properties of an interstitial free steel (IF) was investigated. Symmetric cold rolling yields α- and γ-fibers, which are enhanced as deformation increases. Moreover, α-fiber weakening occurs due to recrystallizations, improving formability. The same fibers are produced by asymmetric cold rolling, but in this case, the γ-fiber is slightly shifted in psi, which is one of Euler angles second ROE's notation1,2, and more homogeneous than in symmetric rolling. The best mechanical properties were achieved by asymmetric cold rolling/annealed with about 80% deformation.

Dislocations are responsible for most aspects of plastic deformation in metals. In this work, the dislocation density, ρ, in brass was estimated after different deformation processes via line broadening of X-ray diffractograms using the Convolutional Multiple Whole Profile Program (CMWP) and by Transmission Electron Microscopy (TEM). In addition, we attempted to evaluate, on a global basis, the influence of crystallographic texture in ρ analysis, making sure that the results obtained by XRD could be trusted even in samples with moderate levels of texture. For this, we compared the ρ values for α brass samples (66% Cu and 34% Zn) with different levels of texture, one deformed by cold rolling and the other by equal channel angular extrusion (ECAE).The results suggest that using CMWP program it was possible to satisfactorily estimate the dislocation density in α brass. It also the was shown that the results by XRD and by TEM were self-consistent in two samples texturized to different degrees.

The effects of asymmetric and conventional deformations and annealing on the microstructure of non-grain-oriented (NGO) 3 wt% silicon steel were analyzed by x-ray diffraction, optical microscopy and magnetometry. The results suggest that pure asymmetric rolling tends to lessen magnetic losses. However, intermediate annealing resulted in lower planar anisotropy, which could be estimated from the magnetic anisotropy theory. In this work, it was shown that this theory is able to predict the J50 magnetic polarization values using crystallographic texture.