Phase prediction, microstructure and high hardness of novel light-weight high entropy alloys

Guided by CALPHAD modeling, low-density and multiphase three novel High Entropy Alloys (HEAs), Al40Cu15Cr15Fe15Si15, Al65Cu5Cr5Si15Mn5Ti5 and Al60Cu10Fe10Cr5Mn5Ni5Mg5 were produced by large scale vacuum die casting. A mixture of simple and complex phases was observed in the as-cast microstructures, which demonstrates good agreement with CALPHAD results. The measured densities varied from 3.7 g/cm3 to 4.6 g/cm3 and microhardness from 743 Hv to 916 Hv. Finally, the hardness of all the light-weight HEAs (LWHEAs) with densities below 4.6 g/cm3 manufactured to date were reviewed. The hardness of Al40Cu15Cr15Fe15Si15 and hardness to density ratio of Al65Cu5Cr5Si15Mn5Ti5 are the highest of all LWHEAs reported up to date.This work has been partially funded by the Basque government through the Project Elkartek: KK-2017/0000

Students’ Perception about Sustainability in the Engineering School of Bilbao (University of the Basque Country): Insertion Level and Importance

Almost three decades have passed since the Rio declaration, and after numerous initiatives developed to include sustainability in higher education, with the support of Education for Sustainable Development, it is worth wondering at what point is the process of inserting sustainability in university degrees. To clarify this question, engineering students were inquired, at the University of the Basque Country (UPV/EHU), about their perception of the insertion-level of sustainability and the importance they give to it (in environmental, social, and economic dimensions). The novelty of this study lies in the use of a new questionnaire, based on the students’ activity. The instrument was designed ad hoc and was previously validated for this study. The results indicate a low insertion level of sustainability in its three dimensions in three engineering degrees analysed. Nevertheless, the research also shows that the students give great importance to Sustainable Development (SD), either in academic, personal, or professional spheres. The low insertion level of SD and the high interest of students should be considered by the academic institution as an opportunity to deep in its holistic approach to promote the integration of SD in university curricula, not only in engineering degrees.This work has been carried out within the educational innovation project PIE 135/2019-2020, subsidized by the vice-chancellor’s office for innovation, social commitment, and cultural action of UPV/EHU

Evolution of Microstructure during Isothermal Treatments of a Duplex-Austenitic 0.66C11.4Mn.9.9Al Low-Density Forging Steel and Effect on the Mechanical Properties

In the last decades, low-density steels for forging have increasing interest in the automotive industry, and good mechanical properties are required for their real application. This paper describes the results obtained for a 0.66C11.4Mn9.9Al duplex austenitic low-density steel after applying a set of isothermal treatments at different combinations of time and temperature, aimed to promote kappa carbide precipitation, and improve the mechanical properties obtained with a water quenching treatment. The effects of the different isothermal treatments on the microstructure and on the mechanical properties have been analyzed and compared to those obtained from a quenching heat treatment. We found that isothermal treatments in the range temperature between 550–750 °C promoted the profuse precipitation of coarse kappa carbides at grain boundaries, which dramatically reduced the ductility of the alloy, whereas a traditional quenching treatment resulted in a better combination of ductility and mechanical strength.This research has been carried out with a financial grant of the Basque Government under its ELKARTEK Research Program, KK-2016/00029-ABADE project and KK-2018/00016-COFADEN project

Aprendizaje servicio+aprendizaje basado en proyectos: un binomio de éxito para trabajar el compromiso social y la ciencia de materiales en estudios universitarios de ingeniería

El aprendizaje basado en proyectos (ABP) ha demostrado ser una metodología eficaz para la adquisición de conocimientos y competencias clave en el ámbito universitario, del mismo modo las experiencias Service Learning (SL) permiten trabajar la Responsabilidad Social Universitaria (USR). Sin embargo, el nivel de adquisición de competencias depende en gran medida de la metodología docente empleada. En este trabajo se muestra la implementación y el desarrollo de una experiencia ABP de aprendizaje-servicio, en una asignatura de grado de ingeniería y en el ámbito de ciencia de los materiales. Se presentarán también los resultados obtenidos, así como las principales conclusiones a las que se ha llegad

Towards Competencies os Sustainability in Engineering Degrees: Project based service-learning experiences

Comunicació presentada al 13th International Conference on Society & Materials, SAM13 (Pisa, 20-21 May 2019)In the present work, a series of collaborative service-learning (SL) experiences carried out in the Universitat Jaume I de Castelló and University of the Basque Country will be presented. These experiences have been developed with in undergraduate courses,bachelor thesis and master thesis. The work points out how these experiences can serve as a toolf or teaching coordination at various levels: horizontal coordination with in a year in one degree, coordination between different degrees orinter-university coordination. The potential of these experiences makes them a very powerful methodological tool that can help not, only the students and the extra curricular agents involved, but also the teaching itself

Podium NIDAS

Duración (en horas): Más de 50 horas - Destinatario: ProfesorEl equipo de estudiantes debe realizar una selección de los materiales que precisa para construir un podium de entrega de trofeos. El diseño del podium es libre, siempre que cumpla los requisitos que les propone el escenario del proyecto. La selección de materiales se justificar en el contexto de la naturaleza del material, el proceso de fabricación de cada pieza y las soluciones que se proponen para realizar las uniones entre piezas

Different Phenomena Encountered during Dilatometry of Low-density Steels

In recent decades, highly alloyed low-density steels are being developed to reduce the weight of different automotive parts. Dilatometry can be a very useful experimental technique to understand phase transformations during heating or cooling of new low-density steel alloys. When performing dilatometry measurements some assumptions are made such as the homogeneity of the sample material tested during the experiment. In this study, dilatometry tests were performed for two different low-density steels, and the variations of the composition between the surface and the inner part of the sample were analyzed. The migration of manganese by diffusion from the interior of the samples and finally its evaporation on the surface under vacuum were observed. This compositional gradient generated in the samples may influence the veracity and interpretation of the results obtained in dilatometry when working with high manganese steel alloys. The detachment of surface grains created by this compositional change near the surface of the samples is also investigated.This research was funded by the Basque Government under its ELKARTEK Research Program, KK-2016/00029-ABADE project and KK-2018/00016-COFADEN projec

University Social Responsibility towards Engineering Undergraduates: The Effect of Methodology on a Service-Learning Experience

Service-Learning (SL) experiences enable University Social Responsibility (USR) to be worked on in engineering studies as a core of education for Sustainability. The combined use of such experiences with active student-centered teaching methodologies fosters the acquisition of general and specific competences. On the basis of students’ perception, this study investigated and sought evidence of empirical foundations to understand whether and how Project Based Learning (PBL) affects the acquisition of USR-related competences when SL experience was implemented as the regular exercise in core courses in engineering studies. This research studied 100 second year undergraduate students in Industrial Design Engineering and Product Development. The students were divided into two groups, one of which experienced Service-Learning only in one class activity while the other group carried out a PBL activity. A survey consisting of 28 items was delivered to all these students and their answers were analyzed from a descriptive statistics viewpoint to understand how the students perceived their degree of attainment of USR competences. The findings suggest a clear difference between the methodologies used, which shows that PBL methodology may lead to a greater acquisition of USR competences than SL activity

Evolution of Microstructure during Isothermal Treatments of a Duplex-Austenitic 0.66C11.4Mn.9.9Al Low-Density Forging Steel and Effect on the Mechanical Properties

In the last decades, low-density steels for forging have increasing interest in the automotive industry, and good mechanical properties are required for their real application. This paper describes the results obtained for a 0.66C11.4Mn9.9Al duplex austenitic low-density steel after applying a set of isothermal treatments at different combinations of time and temperature, aimed to promote kappa carbide precipitation, and improve the mechanical properties obtained with a water quenching treatment. The effects of the different isothermal treatments on the microstructure and on the mechanical properties have been analyzed and compared to those obtained from a quenching heat treatment. We found that isothermal treatments in the range temperature between 550–750 °C promoted the profuse precipitation of coarse kappa carbides at grain boundaries, which dramatically reduced the ductility of the alloy, whereas a traditional quenching treatment resulted in a better combination of ductility and mechanical strength.This research has been carried out with a financial grant of the Basque Government under its ELKARTEK Research Program, KK-2016/00029-ABADE project and KK-2018/00016-COFADEN project

Design, Microstructure and Mechanical Properties of Cast Medium Entropy Aluminium Alloys

In this work, the design, microstructures and mechanical properties of five novel non-equiatomic lightweight medium entropy alloys were studied. The manufactured alloys were based on the Al65Cu5Mg5Si15Zn5X5 and Al70Cu5Mg5Si10Zn5X5 systems. The formation and presence of phases and microstructures were studied by introducing Fe, Ni, Cr, Mn and Zr. The feasibility of CALPHAD method for the design of new alloys was studied, demonstrating to be a good approach in the design of medium entropy alloys, due to accurate prediction of the phases, which were validated via X-ray diffraction and scanning electron microscopy with energy dispersive spectroscopy. In addition, the alloys were manufactured using an industrial-scale die-casting process to make the alloys viable as engineering materials. In terms of mechanical properties, the alloys exhibited moderate plastic deformation and very high compressive strength up to 644 MPa. Finally, the reported microhardness value was in the range of 200 HV0.1 to 264 HV0.1, which was two to three times higher than those of commercial Al alloys.The authors gratefully acknowledge the financial support of the Basque Government through the project Elkartek: KK-2017/00007 and KK-2018/00015