Análisis microestructural de materiales procesados por deformación plástica severa

NATALIA S. DE VINCENTIS; MARTINA AVALOS; ANDREA KLIAUGA; MAURIZIO FERRANTE; H.-G. BROKMEIER; BOLMARO, RAÚL E.

Santa Fe

Congreso; IBEROMAT XIII 14 SAM - CONAMET XIII Simposio Materia; 2014

The mechanical properties of a material are determined by its microstructure, therefore it must be subjected to certain thermomechanical processes that willconfer it with the desired structure for its application. Severe Plastic Deformation techniques (SPD) (such as Equal Channel Angular Extrusion (ECAE) orAccumulative Roll Bonding (ARB)) produce high level of shear deformation, transforming the original structure into an arrangement of sub-micrometric ornanometric grains and dislocation cells. The analysis of the microstructure developed by a material can be achieved using X-ray diffraction technique, becausethe defects introduced in a material affect its diffraction pattern. The use of any of the micromechanical models that correlate the changes in the pattern and themicrostructure lead to an estimation of dislocation and stacking fault density and average domain size. Some of the mentioned models are Williamson-Hall plotand Convolutional Multiple Whole Profile. For a complete analysis of the microstructure it is possible to use Electron Backscatter Diffraction (EBSD) whichwhen implemented in a scanning electron microscope allows both the observation of the microstructure of the material and the evaluation of crystal orientationand misorientation on each point in the analyzed area, bringing information that complements the data observed using x-ray diffraction. This paper presents theanalysis of the microstructure developed in a F138 steel deformed by ECAE and rolling. The information obtained using the techniques mentioned earlierallowed to understand the different stages of the deformation process, identifying both analytically and graphically the presence and frequency of dislocationarrays and stacking faults.