A NEW TECHNIQUE OF METAL RAPID PROTOTYPING USING FUSIBLE ALLOY AND WATER-SOLUBLE CASTING MOLD

摘要

Some applications of rapid prototyping require metal fabrication without heavy equipment like furnaces. We suggest a new rapid prototyping technique, the "WAC process", which uses fusible alloy for these applications. Bi-Sn eutectic alloy has a melting point lower than 140°C, so it is possible to cast the molten alloy into resin molds, those are easily produced by commercial fabricators. Use of eutectic alloy presents a problem of poor mechanical characteristics, which narrows the application field. We tried to improve the alloy characteristics by adding another element to the alloy, and succeeded in increasing its yield stress by 50 %. Another problem we encountered was that conventional casting molds should be provided with parting planes, but the design of their shapes is very difficult, so we proposed a method using water-soluble amino acid salt as the mold material. Some experiments were carried out to confirm suitability of the WAC process.