Research On Application Of DSPC Via SLS

Selective Laser Sintering technology,shorted as SLS,as a branch of rapid prototyping, abbreviated to RP, has attracted the researchers'much attention in the domain of material processing for its wide ranges of forming materials and materials recycled.This dissertation revealed the casting moulds of precoated resin sand are sintered by SLS when castings are made, which is a new way of direct shell production casting, shorted as DSPC. In this paper, the processing parameters of sintering precoated resin sand typed ZFS-GD and used for foundry, such as laser power, scanning speed, preheating temperature and slicing thickness, were studied via carrying out an orthodoxy experiment and the optimized results of 32.5W, 2200mm/s, 55℃,and the 0.28mm were achieved. Simultaneously, in the software environment of Pro/E, the models of casting moulds were reversed by its casting model designed in advance under the mould-design module. Adding the system of running channel and casting head, the casting moulds were completed. Applying SLS technology, the precoated resin sand were sintered to form the casting moulds, thus realized the integration of CAD/CAM of the casting moulds. As the strength of the"green parts"that have been obtained with SLS was too low to be cast, the processing parameters of post-treatment were researched and the results of which that the heating temperature was 180℃and the socking time was 6 hours were acquired. The"green parts"conversed into"brown parts"through heat intensifying and keeping warm and then can be used to cast. Finally, the precise metal castings of ZL102, HT200 and ZG25 alloys were cast with these casting moulds, and their dimension precision and finish precision were analyzed. As a whole, the new process of research on application of DSPC via SLS were explored, investigated, improved and perfected from manufacturing the simple box-shaped castings to the complicated wheel-shaped castings step by step.On the ground of sintering precoated resin sand with SLS, the casting moulds were achieved with software reverse method creatively, combined SLS with DSPC, and the castings were cast successfully. Thus the integration of digital manufacturing on mould CAD/CAM, SLS, and DSPC is realized, and provides an agile, advanced, and rapid means of trail-manufacturing, unit production, and small batch production.