1,721,048 research outputs found
Offshoring vs further offshoring: A multi-level analysis on the firm-, country-and industry-specific drivers of business model reconfiguration
No full textStudy of the direct metal deposition of AA2024 by electrospark for coating and reparation scopes
Full text linkElectroSpark Deposition (ESD) is a pulsed micro-welding process that is capable of depositing wear and corrosion resistance deposit to repair, improve, and to extend the service life of the components and tools. Major new applications have taken place in gas turbine blades and steam turbine blade protection and repair, and in military, medical, metal-working, and recreational equipment applications. In this study, the ESD technique was exploited to fabricate 2024 aluminum alloy deposit on a similar substrate. The deposits were deposited using different process parameters. Heat input was varied on three levels. The outcoming microstructure was analyzed by optical and scanning electron microscopies. The deposit was characterized by the overlapping of layers with a mixed microstructure. The average hardness was independent from the process parameters. Both porosity inside the deposits and cracks at the deposit/substrate interface were detected. The porosity lowered with the heat input and increased the average length of cracks
Effect of ElectroSpark process parameters on the WE43 magnesium alloy deposition quality
No full textThis research aims to investigate the effects of process parameters on the quality of WE43 coatings deposited on homologue substrate by ElectroSpark Deposition (ESD) technology. ESD is new technology used to apply coatings or for the restoration and refurbishment of worn or damaged high valued parts. The depositions were processed using five different levels of Energy input (Es, Spark Energy). The microstructure of both the base material and deposits cross-section were characterized by optical and scanning electron microscopies. Also, X-ray diffraction technique was used. In addition, stereological studies of the through-thickness heterogeneities of the deposits (e.g., voids) were performed. The mechanical properties were evaluated by Vickers micro-hardness. The results show that the deposits exhibited a fine grained microstructure due to the rapid solidification. The average micro-hardness values of the deposits are lower than that of the substrate and distributed in a small range (49-60 HV). The lower hardness of the deposits respect to the base material is due to the presence of defectiveness such as spherical, laminar and random shaped voids. The defects area percentage inside the deposits remains well below than 11%. All the deposits were mainly affected by laminar morphology defects. The results indicate that the deposits defectiveness decreases as the energy input increases
Studio dell’insorgenza di fenomeni corrosivi in campioni di bronzo mediante tecnica di proiezione di frange,
No full textA brief analysis of corrosion-induced degradation in metallic materials: a challenge in additive manufacturing
No full textAdditive manufacturing (AM) has revolutionised the production of metal components, opening up the possibility of designing and producing parts previously unattainable with traditional manufacturing techniques. Nevertheless, concerns remain regarding these AM-produced parts’ long-term durability and reliability. Several studies have shown that material degradation (corrosion) ranks among the foremost factors responsible for constraining the performance of metal parts. It is well-established that corrosion undermines the functionality of a component by deteriorating its mechanical characteristics, including ductility, fatigue resistance, as well as its physical and elastic properties. This review delves into the various corrosion-induced degradation mechanisms that affect metallic materials, particularly those fabricated using the Additive Manufacturing (AM) process. Furthermore, the review highlights the importance of proper post-processing techniques as a key factor in improving the durability and reliability of AM components, offering valuable insights for readers to strengthen their AM practices
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