Abstract A previous constitutive modeling for single-phase steels is extended using the mixing law to predict the behavior of hot deformation in the dual phase ferritic-austenitic intercritical zone of Fe-C-Mn-Si alloys. Mixing law considers two phases instead one, so one phase formula was modified. The constant’s values used represents average values to the same conditions in austenitic and ferritic model. The amount of each phase is determined as function of temperature and chemical composition. The developed constitutive modeling is validated by comparing the theoretical stress-strain curves with experimental isothermal uniaxial compression tests of 1008 and 1035 carbon steels at different temperatures and strain rates. The compression tests were carried out in a dilatometer with the compression load at strain rate of 10-3, 10-2 and 10-1 s-1. A good agreement was obtained between the calculated and experimental results over different stages of deformation and hardening. Microstructural analysis was also carried out to relate the deformation results to the microstructure of the steels. Finally, a general constitutive equation has been proposed for hot deformation of steels in the intercritical zone.

Abstract In this work, a series of experimental activities that have been generated using Zinc and Zn-Al alloys, as a didactic resource for teaching in the field of Science, Engineering or Materials Technology; of the Manufacturing Processes and Surface Engineering areas. We also propose experiences that can be included in the future, and, finally, we present an analysis of the advantages and limitations of the use of zinc and Zn-Al alloys, which are abundant and underused resources in our countries, as an attractive alternative to improve the results of the teachinglearning process in these subjects. Among the advantages of these resources, it is important to point out that the processing occurs at temperatures much lower than those conventionally used with steels and that there is a range of additional options for teaching different processes.

Resumen En este trabajo se reúnen una serie de actividades experimentales que se han generado, usando al Zinc y a las aleaciones Zn-Al como recurso didáctico para la enseñanza de materias del campo de los Materiales, de la Manufactura y de la Ingeniería de Superficies. Se proponen, asimismo, experiencias que se pueden incluir en el futuro y se presenta un análisis de las ventajas y limitaciones de la utilización didáctica del zinc y las aleaciones Zn-Al, todo esto como una alternativa atractiva para mejorar los resultados del proceso enseñanzaaprendizaje de estas asignaturas. Entre las ventajas de estos recursos conviene señalar que el procesamiento ocurre a temperaturas mucho menores de las convencionalmente empleadas con aceros y que se puede tener una gama de opciones adicionales para la enseñanza de procesos novedosos.

El objetivo del artículo es dar una visión global de uno de los más activos campos de investigación en el procesamiento mecánico de materiales metálicos como es la obtención de materiales con grano nanométrico y ultrafino a través de la severa deformación plástica SDP. Se realiza una descripción de las más importantes técnicas pertenecientes a SDP, como lo son: la molienda mecánica, presión en canal angular constante, torsión a alta presión, unión por laminación acumulada, extrusión-compresión refiriéndose a los principios fundamentales, ventajas y limitaciones de cada una de ellas. Se incluyen resultados experimentales obtenidos por los presentes autores en la preparación de hierro y cobre. Adicionalmente, se presenta el gran potencial que tienen estos materiales en diferentes campos de aplicación, especialmente en la industria aeroespacial. Finalmente, se hace referencia a tendencias actuales de investigación comprendiendo dos áreas fundamentales, el estudio del comportamiento microestructural y mecánico, y el desarrollo de métodos de procesamiento escalables a nivel industrial.

The aim of this paper is to provide a general overview of nanocrystalline and ultra-fine grain material production using severe plastic deformation (SPD), this being one of the most active research fields in the mechanical processing of materials. The paper gives an explanation of the more important SPD techniques (mechanical milling, equal channel angular pressing, high pressure torsion, extrusion-compression and accumulated roll-bond) as regards fundamental principles, advantages and limitations. Some experimental results for iron and copper obtained by this paper’s authors are attached. These materials’ great potential is shown in several fields of use, especially in the aerospace industry. Current research prospects are also referred to in terms of structural and mechanical behaviour and the development of large-scale industrial processing.