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Laser-based powder bed fusion (L-PBF) is nowadays the preeminent additivemanufacturing (AM) technique to produce metal parts. Nonetheless, relatively few metal powders are currently available for industrial L-PBF, especially if aluminum-based feedstocks are involved. In order to fill the existing gap, A357.0 (also known as A357 or A13570) powders are here processed by L-PBF and, for the first time, the fatigue behavior is investigated in the as-built state to verify the net-shaping potentiality of AM. Both the low-cycle and high-cycle fatigue areas are analyzed to draw the complete Wohler diagram. The infinite lifetime limit is set to 2 × 106 stress cycles and the staircase method is applied to calculate a mean fatigue strength of 60 MPa. This value is slightly lower but still comparable to the published data for AlSi10Mg parts manufactured by L-PBF, even if the A357.0 samples considered here have not received any post-processing treatment. [ABSTRACT FROM AUTHOR]

Purpose – The purpose of this paper is to report an interdisciplinary, cooperative-learning project in a second-year course within the “Enzo Ferrari” Master of Science Degree in Mechanical Engineering. The work aims to raise awareness of the educational impact of additive manufacturing and reverse engineering. Design/methodology/approach – Students are asked to develop, concurrently, the design and the manufacturing solution for an eye-tracker head mount. A digital head model is reverse engineered from an anatomical mannequin and used as an ergonomic mock-up. The project includes prototype testing and cost analysis. The device is produced using additive manufacturing techniques for hands-on evaluation by the students. Findings – Results of the presented case study substantiate the authors’ belief in the tremendous potential of interdisciplinary project-based learning, relying on innovative technologies to encourage collaboration, motivation and dynamism. Originality/value – The paper confirms a spreading conviction that the soon-to-be engineers will need new practice-oriented capabilities to cope with new competitive scenarios. Engineering education must adapt to the social, rather than industrial, revolution that is being brought about by additive fabrication. [ABSTRACT FROM AUTHOR]

Purpose – The purpose of this paper is to evaluate how the direct access to additive manufacturing (AM) systems impacts on education of future mechanical engineers, within a Master’s program at a top Italian University. Design/methodology/approach – A survey is specifically designed to assess the relevance of entry-level AM within the learning environment, as a tool for project development. The survey is distributed anonymously to three consecutive cohorts of students who attended the course of “computer-aided production (CAP)”, within the Master of Science Degree in Mechanical Engineering at Politecnico di Torino. The course includes a practical project, consisting in the design of a polymeric product with multiple components and ending with the production of an assembled prototype. The working assembly is fabricated by the students themselves, who operate a fused deposition modelling (FDM) machine, finish the parts and evaluate assemblability and functionality. The post-course survey covers diverse aspects of the learning process, such as: motivation, knowledge acquisition, new abilities and team-working skills. Responses are analyzed to evaluate students’ perception of the usefulness of additive technologies in learning product design and development. Among the projects, one representative case study is selected and discussed. Findings – Results of the research affirm a positive relationship of access to AM devices to perceived interest, motivation and ease of learning of mechanical engineering. Entry-level additive technologies offer a hands-on experience within academia, fostering the acquisition of technical knowledge. Research limitations/implications – The survey is distributed to more than 200 students to cover the full population of the CAP course over three academic years. The year the students participated in the CAP course is not tracked because the instructor was the same and there were no administrative differences. For this reason, the survey administration might be a limitation of the current study. In addition to this, no gender distinction is made because historically, the percentage of female students in Mechanical Engineering courses is about 10 per cent or lower. Although the answers to the survey are anonymous, only 37 per cent of the students gave a feedback. Thus, on the one hand, impact assessment is limited to a sample of about one-third of the complete population, but, on the other hand, the anonymity ensures randomization in the sample selection. Practical implications – Early exposure of forthcoming designers to AM tools can turn into a “think-additive” approach to product design, that is a groundbreaking conception of geometries and product functionalities, leading to the full exploitation of the possibilities offered by additive technologies. Social implications – Shared knowledge can act as a springboard for mass adoption of AM processes. Originality/value – The advantages of adopting AM technologies at different levels of education, for diverse educational purposes and disciplines, are well assessed in the literature. The innovative aspect of this paper is that the impact of AM is evaluated through a feedback coming directly from mechanical engineering students. [ABSTRACT FROM AUTHOR]

Metal additive manufacturing is now taking the lead over traditional manufacturing techniques in applications such as aerospace and biomedicine, which are characterized by low production volumes and high levels of customization. While fulfilling these requirements is the strength of metal additive manufacturing, respecting the tight tolerances typical of the mentioned applications is a harder task to accomplish. Powder bed fusion (PBF) is a class of additive manufacturing in which layers of metal powder are fused on top of each other by a high-energy beam (laser or electron beam) according to a computer-aided design (CAD) model. The quality of raw powders for PBF affects the mechanical properties of additively manufactured parts strongly, and therefore it is crucial to avoid the presence of any source of contamination, particularly cross-contamination. In this study, the identification and quantification of cross-contamination in powders of Ti-6Al-4V and maraging steel was performed using scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) techniques. Experimental results showed an overall good reliability of the developed method, opening the way for applications in machine learning environments. [ABSTRACT FROM AUTHOR]

Rapid solidification with high cooling rates of metal alloys determines both the improvement of mechanical properties, due to the finishing of the structure, as well as obtaining metastable structures in the form of supersaturated or amorphous/nano solid solutions, which could potentially confer the material outstanding properties. It is of particular interest to use the energies released during the heating stage for these materials, due to the potentially lower input energy required to melt/fuse these materials. This phenomenon could add to the development and diversification of additive manufacturing technologies. The paper presents results concerning the structural development and phase transformation of metastable structures from Al–Si–Ni-based alloys, obtained by melt spinning and atomization techniques. It was observed that the structural transformations occurring during the heating process, starting from metastable structures, generate significant amounts of energy. This is of practical importance in the use of metallic powders in additive manufacturing technology, due to potentially reduced energy input. [ABSTRACT FROM AUTHOR]

In spite of the fast growth of laser-based powder bed fusion (L-PBF) processes as a part of everyday industrial practice, achieving consistent production is hampered by the scarce repeatability of performance that is often encountered across different additive manufacturing (AM) machines. In addition, the development of novel feedstock materials, which is fundamental to the future growth of AM, is limited by the absence of established methodologies for their successful exploitation. This paper proposes a structured procedure with a complete test plan, which defines step-by-step the standardized actions that should be taken to optimize the processing parameters and scanning strategy in L-PBF of new alloy grades. The method is holistic, since it considers all the laser/material interactions in different local geometries of the build, and suggests, for each possible interaction, a specific geometry for test specimens, standard energy parameters to be analyzed through a design of experiment, and measurable key performance indicators. The proposed procedure therefore represents a sound and robust aid to the development of novel alloy grades for L-PBF and to the definition of the most appropriate processing conditions for them, independent of the specific AM machine applied. [ABSTRACT FROM AUTHOR]

Even though additive manufacturing (AM) techniques have been available since the late 1980s, their application in medicine is still striving to gain full acceptance. For the production of dental implants, the use of AM allows to save time and costs, but also to ensure closer dimensional tolerances and higher repeatability, as compared to traditional manual processes. Among the several AM solutions, Laser Powder Bed Fusion (L-PBF) is the most appropriate for the production of metal prostheses. The target of this paper was to investigate the mechanical and microstructural characteristics of Co–Cr–Mo and Ti–6Al–4V alloys processed by L-PBF, with a specific focus on secondary anisotropy that is usually disregarded in the literature. Tensile specimens were built in the EOSINT-M270 machine, along different orientations perpendicular to the growth direction. Density, hardness, and tensile properties were measured and the results combined with microstructural and fractographic examination. For both alloys, the results provided evidence of high strength and hardness, combined with outstanding elongation and full densification. Extremely fine microstructures were observed, sufficient to account for the good mechanical response. Statistical analysis of the mechanical properties allowed to attest the substantial absence of secondary anisotropy. The result was corroborated by the observations of the microstructures and of the failure modes. Overall, the two alloys proved to be high-performing, in very close agreement with the values reported in the datasheets, independently of the build orientation. [ABSTRACT FROM AUTHOR]