1,721,052 research outputs found
Laser forming of glass laminate aluminium reinforced epoxy (GLARE): On the role of mechanical, physical and chemical interactions in the multi-layers material
No full textThe present work concerns the laser forming of Fiber-Metal Laminates (FMLs) by a high power diode laser source. FMLs are made of different layers of metal and composite material. The wide difference in the thermo-mechanical and physical properties of the different layers within FMLs makes them extremely problematic to be reprocessed. In particular, the economic shaping of FMLs in complex shapes is practically impossible, limiting greatly their field of application. Therefore, this manuscript explores the possibility of using laser forming to reprocess FMLs and obtain final components with precisely controlled bending radii. For this purpose, the effect of the laser operating parameters, namely laser power, scanning speed and number of passes, on the final shapes of FMLs was investigated. Secondly, further tests were also performed to obtain other complex shapes on FMLs from multiple laser scanning paths, side by side and equidistant on the substrates. An analysis of the failure of the substrates during the shaping process was also performed, with particular emphasis on deformation mechanisms, interfacial delamination and thermal alteration of the layers. The experimental results showed the good viability of laser reprocessing to shape FMLs, thus opening up new possible applications of this class of materials in aeronautical and aerospace applications
Se con la formatura laser si segue la tecnica origami
No full textIn this work, the achievement of complex shapes by a diode laser forming process operated according to origami's technique is investigated. In particular, the manufacturing of a geometric item called "origami spoon" was looked into, trying to form the bottom spoon alone. The experimental approach allowed the selection of a technological window, in which high bending angles are achievable without impairing the surface. In addition, required paths and appropriate operational routes to conform the most the manufactured items to the prescribed design were identified
Neural network approach for estimating the hole damage in drilling process of reactive powder concrete (rpc)
No full textThis study deals with the analysis of hole damage in the drilling of reactive powder concrete (RPC). Attention was first focused on the definition of an original approach on the basis of digital image processing (DIP) to quantify the extent of the damage. Then, an experimental approach, on the basis of the design of experiments (DoE), was performed to evaluate the influence of drilling operational parameters (namely, cutting speed, feed hole diameter) on the thrust force, torque RPC hole accuracy. The extent of hole damage was found to be influenced by the settings of feed and hole diameter, with cutting speed playing a minor role. Tool vibrations and troublesome centering procedures of the tools during drilling further complicated the interpretation of the hole damage
Comparative life cycle assessment and multi-criteria decision analysis of coffee capsules made with conventional and innovative materials
No full textOn the use of Fluidized Bed Coating (FBC) to deposit thin Al2O3 films onto metal substrates
No full textFluidised Bed Coating (FBC) is a viable and low-cost technique to apply, at ambient temperature, thin adherent ceramic coatings onto metal and non metal substrates. Al2O3 films, by virtue of its special thermo-mechanical, chemical, electrical and optical properties, belong to a class of ceramic coatings of particular interest in several manufacturing processes. In this respect, the present paper reviews selected applications in manufacturing of Al2O3 coated aluminium substrates. In particular, the use of fluidised bed deposited thin Al2O3 films has been reported as surface overlay coatings to improve the fatigue behaviour of aluminium components, as absorption and thermal barrier coatings in sheet laser forming and, finally, as anti-wear protective coatings
Advances in Laser Processing of Metal Matrix Composites (MMCs)
No full textThe present work deals with the application of a High Power Diode Laser (HPDL) to improve the mechanical properties of Al2O3 particle-reinforced Aluminum Matrix Composites (AMCs). An experimental plan in which laser power and interaction time were individually varied was carried out to evaluate the influence of both process parameters on the surface performance of the AMCs. In this respect, the evolution of their surface morphology was assessed by contact-gauge profilometry. Further samples were, then, analyzed by FIMEC micro-indentation test, depth-sensing load controlled scratch and wear test. Experimental findings show that mechanical and tribological proprieties of the laser treated substrates can be considerably improved, although in an operating range of process parameters rather narrow. Finally, an analytical model was proposed to correlate the wear performance of the AMCs investigated to their morphological and mechanical properties
Evaluation and Classification of Hole Damage in Drilling Process of Reactive Powder Concrete (RPC) Using Neural Network Analysis
No full textEnergy absorption of PLA-based metamaterials manufactured by material extrusion: dynamic loads and shape recovery
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