The texture development of ECAP processed AA1050aluminum, before and after a final anneal: effect of the initial texture

Equal Channel Angular Pressing (ECAP) can be used to control deformation and annealing textures. The initial texture has a significant role on texture development and intensity after deformation and anneal. In this work AA 1050 Al samples with different initial textures and initial strain of 0.3 were deformed in a I20° ECAP die. Deformation followed route A, yielding equivalents strains of 1 and 3 above the initial. After ECAP one of the samples was rolled to a thickness reduction of 70%. Texture evaluation was performed by x-ray analysis in the as deformed state and after annealing at 350°C for 1 h, by calculating orientation distribution functions. The microstructure was observed by optical and scanning electron microscopy.Fil: Vega, M. C. V.. Universidade Federal Do Sao Carlos. Departamento de Engenharia de Mteriales; BrasilFil: Piva, B. H.. Universidade Federal Do Sao Carlos. Departamento de Engenharia de Mteriales; BrasilFil: Bolmaro, Raul Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Física de Rosario (i); ArgentinaFil: Ferrante, M.. Universidade Federal Do Sao Carlos. Departamento de Engenharia de Mteriales; BrasilFil: Kliauga, A. M.. Universidade Federal Do Sao Carlos. Departamento de Engenharia de Mteriales; Brasi

Tissue equivalence correction for silicon microdosimetry detectors in boron neutron capture therapy

Reverse-biased silicon p-n junction arrays have been proposed as microdosimetry detectors. The tissue equivalence of such detectors in boron neutron capture therapy (BNCT) is discussed. A comparison of the range-energy relationships of H, He, C, and Li ions in tissue (ICRU-muscle) and silicon is given. A simple geometrical scaling (~0.63) of linear dimensions is required to convert microdosimetric energy deposition measurements performed in silicon to equivalent deposition in tissue. The Monte Carlo technique is used to examine energy deposition for two simple geometrical cases applicable to BNCT

Microstructure and texture of duplex stainless steel after melt-spinning processing

The microstructure and texture of melt-spun UNS S31803 (DIN W. Nr. 1. 4462) duplex stainless steel were analyzed after casting and solution treatment. The cast ribbons contained austenite (gamma) and ferrite (alpha or delta) with roughly equal compositions. The alpha and gamma had < 100 > and < 110 > partial fiber textures, respectively. After solution treatment, the texture was maintained, the amount of gamma phase increased, and the alloying elements were partitioned as expected, according to whether they were ferrite or austenite stabilizers. (c) 2006 Elsevier Inc. All rights reserved

The influence of deformation path on strain characteristics of AA1050 aluminium processed by equal-channel angular pressing followed by rolling

The present investigation reports on the microstructure evolution, texture development, the nature of the grain boundaries and the tensile and deep drawing behaviour of commercial AA1050 Al processed by Equal Channel Angular Pressing (ECAP) plus rolling. Although in terms of final mechanical strength ECAP and rolling are indistinguishable, the deformation path is substantially different, and this has important consequences on both microstructure and texture. From the spatial distribution of high angle grain boundaries (HAGB) and low angle grain boundaries (LAGB), the fine microstructure and the crystallographic texture, it was concluded that the microstructure is oriented according to the external imposed flow: a spin movement in the ECAP process, which promotes the rotation of the cells inside the original grain, followed by a sliding movement caused by the rolling, leading to grain elongation. The ECAP process is more suitable to promote a higher fraction of HAGBs, and the same time as it reduces the intensity of the bulk crystallographic texture. As a consequence an increase of the penetration depth and deformation strain, as measured by the Erichsen test, was observed in samples processed by 8 ECAP passes, characterized by low texture intensity and a high degree of dynamic recrystallization.Fil: Vega, M. C. V.. Universidade Federal do São Carlos; BrasilFil: Bolmaro, Raul Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: Ferrante, M.. Universidade Federal do São Carlos; BrasilFil: Sordi, V. L.. Universidade Federal do São Carlos; BrasilFil: Kliauga, A. M.. Universidade Federal do São Carlos; Brasi

Strain path dependence of anisotropic microstructure evolution on low Stacking Fault Energy F138 steel

Severe Plastic Deformation (SPD) techniques are widely used nowadays because of the mechanical properties improvements caused by grain refinement and development of dislocation arrays. Diffraction techniques can be used to assess the changes registered in the microstructure through these methods. Two sets of samples of F138 austenitic stainless steel were analyzed in this paper: one set was deformed by ECAE up to two pressings at room temperature, and the other set was cold rolled to 70% reduction and annealed at 600, 700, 800 and 900 °C for 1 h. The microstructural changes were determined using X-Ray diffraction and EBSD, combining both, global and local information and characterizing domain sizes, dislocation and stacking fault densities and misorientation degree and distribution caused by the different thermomechanical processing. It was observed that, despite cold rolling and 2 ECAE passes rendered rather similar von Mises deformations, the microstructure through each deformation method was different: 2 ECAE passes seem to be more effective for grain refinement and generation of equiaxed domains than cold rolling. The more significant twin activation observed in the former sample, because of continuous strain path change, may explain the difference, although dislocation densities and mechanical properties did not differ substantially for both deformation methods.Fil: de Vincentis, Natalia Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: Avalos, Martina Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: Kliauga, A.. Universidade Federal do São Carlos; BrasilFil: Brokmeier, H. G.. Institut für Werkstoffkunde und Werkstofftechnik; Alemania. Helmholtz Zentrum Geesthacht; AlemaniaFil: Bolmaro, Raul Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; Argentin