Development of pattern smelting method with ABS material in Investment Casting process

Investment Casting (IC) is a producing method of high quality casting. It is useful to generate complex geometry in casting product, which cannot be achieved by forging, machining, or machining process with excessive material usage. Currently, IC pattern is made of wax. The wax melts away during the molten metal pouring. In the past, it was stipulated that once a foundry used a wax pattern of particular grades, that it could not be replaced by another grade. This was to avoid the risk of dimensional variety of patterns, coupled with a basic fear of change. The pattern wax compounds have been chosen by foundries with numerous considerations, such as: historical record; the wax the only suitable compound at the time; professional recommendation; and copying from another foundry. Inappropriate wax injector's parameter can create low quality patterns and a ceramic shell. Nowadays, there are wide ranges of material available as an alternative for the IC wax pattern, which in this paper initially highlighted using Acrylonitrile Butadiene Styrene (ABS) as a replacement of conventional pattern material. The pattern with ABS material can be created by Rapid Prototyping Machine (RPM) that is Fused Deposition Modeling (FDM) technology. The experimental outcomes are: there are cracks in the ceramic shell while using the smelting chemical method because ABS material pushed out the shell; perfect ceramic shell with ABS pattern smelting while using burn-out method; and this method can reduce three of seven steps or more efficient about 42.85% of the existing IC process.