Fly ash (FA) is a low-cost industrial waste material mostly composed of oxides. These small, hard particles can be used as reinforcements in composite production. In this study, an A356.0 aluminum alloy reinforced with 4 wt.% FA was synthesized by compo casting and subsequently subjected to multiple passes of equal channel angular extrusion (ECAE) to investigate the influence of intense plastic deformation on the composite hardness and microstructure. Microstructure analysis was performed on an optical microscope and by computer tomography (CT). The as-cast alloy contains a relatively homogeneous microstructure with minor FA agglomerations and very low porosity. The severe plastic deformation induced by ECAE results in a directed structure and additional integration of FA into the matrix with the disappearance of pores. Vickers hardness measurement of aluminum/fly ash (Al/FA) composite was carried out with different indentation loads: 0.196 N (HV0.02), 0.490 N (HV0.05), 0.981 N (HV0.1), and 1.960 N (HV0.2). The results showed that hardness increases after each ECAE pass because of microstructure changes. Already after the first pass, a significant increase in hardness is achieved, ranging from 27% (HV0.05) to 62% (HV0.2). A Meyer’s index (n) value greater than 2 indicates that the hardness of single and double extruded composite depends on the indentation load. Extruded samples show a hardness enhancement with increasing applied load, so the examined composite exhibits a reverse indentation size effect (RISE).

Technology is acting as a catalyst for the transformation towards sustainability in education and as a means of reshaping the educational experience. This transformation is part of an overall transformation in our society, and education should be dedicated to creating satisfied students able to think autonomously, take responsibility for their views, and contribute to society. Both sustainable education and education for sustainability benefit from blended learning, which facilitates participatory teaching and empowers learners. The aim of our research was to determine teachers’ and students’ (a) awareness of the development of digital platforms for teaching and learning, (b) perception of their own digital skills, (c) use and experience of Coursera, and (d) attitudes towards the content and benefits of digital platforms, such as Coursera, for teaching and learning. The analysis was carried out using a questionnaire in which we collected feedback from students and teachers at the University of Sarajevo about their awareness and preferences of the contents offered by Coursera and their readiness to use those additional learning and teaching resources. The results of this study show that there is a lack of awareness of online e-learning platforms among students, with more than half of the sample professing ignorance about these sites. The identified lack of experience and a noticeable lack of motivation could present significant repressors in the transformation of education if not addressed properly.

In this study, metal matrix-based composite (MMC) was subjected to Equal Chanel Angular Pressing (ECAP) in several passes to determine the influence of deformation on the hardness of the samples. Composite based on A356 aluminum alloy and reinforced with Fly Ash (FA) particles was obtained by the compo casting method. The microstructural analyses and microhardness measurements were performed on the cast and pressed samples. Vickers hardness measurement of composite samples was performed with different indentation load sizes: HV0.02, HV0.05, HV0.1 and HV0.2. Results showed that hardness increases after each ECAP pass. The lowest hardness value of 42 (HV0.02) as well as the lowest arithmetical mean value of 46 (HV0.2) was measured at the cast composite. The greatest composite hardness of 107 (HV0.1) and the highest arithmetical mean value of 94 (HV0.1) was measured at the three-time pressed sample. The mathematical model named Meyer’s law was used for data analysis. In the cast sample, a decrease in hardness was detected with increasing indentation load, termed Indentation Size Effect (ISE), was confirmed with Meyers index n = 1.9112 < 2. Pressed samples showed opposite behavior—an increase in hardness with increasing indentation load—where Meyers index n > 2 indicated Reverse Indentation Size Effect (RISE). For all samples, a high coefficient of determination R2 > 0.99 confirmed that Meyer’s law described this phenomenon well.

This paper describes the influence of deformation by equal-channel angular pressing (ECAP) on the solid particle erosion resistance of the AlSi7Mg0.3 alloy and AlSi7Mg0.3 based composite material reinforced with the addition of 4 % of fly ash (FA) particles. Both, alloy and composite samples were produced using the compo-casting method. The samples have been subjected to ECAP in multiple passes with the rotation of samples around the vertical axis for the angle of 90° after each pass. Particles of silicon carbide (SiC) have been used as erodent while their impact angle was varied (30° and 90°). Observed samples of AlSi7Mg0.3 alloy generally showed higher wear resistance at 90° angle where material fatigue predominates, than at a 30° angle where abrasion-related phenomena predominate. On the other hand, AlSi7Mg0.3 based composite material exhibited erosion wear at 30° angle less than at 90° angle after one ECAP pass. Evaluation of the erosion resistance has been made based on mass and volume loss. After two passes of ECAP, the matrix structure of the AlSi7Mg0.3 based composite material, as well as that of the AlSi7Mg0.3 alloy was improved from the aspect of erosion resistance.