Investigations of the effect of injection parameters on the dimensional accuracy of wax patterns used in ceramic shell investment casting

The present investigation is aimed to determine the effects of injection parameters on the dimensional accuracy of the wax patterns, produced by wax injection machine, to be used in ceramic shell investment casting process. The injection parameters viz. time, temperature, die temperature and holding time were considered. Experiments were performed and optimal parameters were determined. Linear and volumetric contractions of wax patterns were measured and dimensional variations were evaluated. Results reveal that an increase in injection temperature increases wax shrinkage, whereas increase in die temperature reduces the wax shrinkage. Slow injection and short holding time reduces dimensional variation in castings.