Optimization of Dimensional Accuracy of Wax Models Manufactured by Rapid Tooling Method
The primary objective of this research is to determine the accuracy of a Typical Gas Turbine Blade wax patterns
which includes common areas in Turbine Blades, such as Airfoil, Platform and Root, produced by soft tooling RTV (room
temperature vulcanization mold) methods, silicone rubber molds and epoxy molds as well as comparing them. It is essential
to use the optimal injection parameters during molding in order to obtain good dimensional accuracy of wax patterns. From
the current study it is noticed that the epoxy mold produces more accurate patterns than the silicone rubber mold.
Furthermore, the range of dimensional changes in various directions of the wax patterns, were obtained. Average Shrinkage
in direction along the length and width of the root in silicone rubber mold are almost 0.6%, 3.5% respectively. And
perpendicular to Platform in direction of Airfoil is 0.6% approximately. Also average shrinkage in epoxy mold in direction
along the length and width of the root are almost 1.1%, 0.6% respectively and perpendicular to Platform in direction of
Airfoil is almost 0.6% too. These studies will help those who apply both rapid tooling and investment casting in turbine
blades production to estimate the changes required in the initial CAD drawings to produce a final optimized casting model
with minimal dimensional inaccuracy.
Keywords- Turbine Blades; Rapid Tooling; Investment Casting; Wax Models