Preliminary experience with sand casting applications of rapid prototyping by selective laser sintering (SLS)

Abstract

The layers fabrication technique, known as Selective Laser Sintering SLS, is widely used. A basic investigation on its application in the field of the fabrication of transitory molds in the foundry industry is the object of this work. In fact, the Selective Laser Sintering (SLS) of pre­covered foundry sands allows the aggregation of adjacent particles with the possibility to realize molds and cores not obtainable with conventional methods.Since LaserCron is widely used for sand casting (by EOS) with SLS, the authors investigated its CO2 laser behavior. The laser effect on sand has been evaluated in terms of sintering thickness and deformations of layers along the z-axis. A full factorial approach has been used in order to evaluate the effects of three controllable factors, i.e. laser power, scan speed, scan spacing, and their interactions, on the layers adhesion, surface quality, and accuracy of the obtained product. Response surface methodology and Analysis of Variance have been used to evaluate SLS process performance, in terms of process parameter evaluation and optimization.The layers fabrication technique, known as Selective Laser Sintering SLS, is widely used. A basic investigation on its application in the field of the fabrication of transitory molds in the foundry industry is the object of this work. In fact, the Selective Laser Sintering (SLS) of pre­covered foundry sands allows the aggregation of adjacent particles with the possibility to realize molds and cores not obtainable with conventional methods.Since LaserCron is widely used for sand casting (by EOS) with SLS, the authors investigated its CO2 laser behavior. The laser effect on sand has been evaluated in terms of sintering thickness and deformations of layers along the z-axis. A full factorial approach has been used in order to evaluate the effects of three controllable factors, i.e. laser power, scan speed, scan spacing, and their interactions, on the layers adhesion, surface quality, and accuracy of the obtained product. Response surface methodology and Analysis of Variance have been used to evaluate SLS proc...