Showing papers by "Giuseppe Casalino published in 2002"

An investigation of rapid prototyping of sand casting molds by selective laser sintering

Abstract: Among the layer fabrication techniques, selective laser sintering (SLS), is widely used for manufacturing various products made of different materials (i.e., polycarbonates, nylons, polyamides, sand casting, metal powders, and others). The SLS of precoated foundry sands allows the aggregation of adjacent particles, which are then cemented by furnace heat treatment. Moreover, geometrically complex molds and cores not obtainable with conventional methods can be realized by this method. In this article, the optimization of laser parameters is reported for fabricating transitory molds for foundry applications. Lasercron sand, a quartz sand with a thin phenolic resin coating often used for SLS applications, was tested. The CO2 and diode lasers were used for this study. After some preliminary tests, experimental design techniques were applied to investigate the influence of some processing parameters, i.e., laser power, scan speed, and scan spacing (hatch). Their interactions were evaluated using response surfa...

Parameter selection by an artificial neural network for a laser bending process

Abstract: Based on thermally induced plastic deformations produced by laser irradiation, metal sheet laser bending can be a valid alternative to dies for rapid prototyping and manufacturing. Some num...

Fem Model Computing Large Deformation in Metal Sheet Forming by High Power Beam

Abstract: The use of high power beam technologies like the laser and the plasma arc has provided a mould-less metal sheet rapid forming technique. This technique can have application either for rapid prototyping and rapid manufacturing of mechanical products. The virtual manufacturing can be a boost for a rapid diffusion of the mould-less sheet forming. Even if the calculations can be cumbersome, the Finite Element Analysis (FEM) is unique for providing geometrical and physical information on product development and manufacturing via computer. Herein, a simplified FEM model for both laser and plasma arch is proposed. In particular, the heat source has been modeled so the computation is easier and faster. The model was validated by comparison with the experimental results and it is able to predict the forming angle, the final shape, and the residual stress of metal sheet induced by high power beam irradiation.