Using metallic resin and aluminum alloy molds to manufacture propellers with RP/RT technique

Purpose - This purpose of this study is to investigate an effective method to manufacture propellers. Design/methodology/approach - The investment casting process and injection molding process have been applied separately to the rapid prototyping/rapid tooling (RP/RT) to obtain metal (Al-Si alloy) propellers and plastic (Acrylonitrile butadiene styrene - ABS) propellers. The two different manufacturing processes were compared following the same master model (MM). The Moldflow software is used to optimize the experimental parameters of the molding. Furthermore, a gypsum type of powder is used to produce the RP MM of the propeller according to the Pro-E software. The RP MM then is filled with a metallic resin material (at room temperature) to obtain a wax mold. Then, this wax mold was coating by dipping the ZrO2 slurry to improve heat resistant ability, and following solidification, and then filled with metal alloy to obtain metal (Al-Si alloy) propellers. Another process, the RP MM by dipping the ZrO2 slurry to increase the heat resistance and then is filled with aluminum alloy and an injection mold can be obtained, the plastic (ABS) propellers can be duplicated. To ensure the precision of dimension and improves the surface roughness for the RT (metallic resin mold and aluminum alloy mold), the contour of the duplicated molds were milling with the high-speed CNC manufacturing program. Findings - The advantage of this process is that combining the RP/RT system with the high-speed CNC machining center enables easy production of injection molds. Originality/value - This process provides engineers with a quick way to fabricate parts and modify the designs. This study demonstrates that this process provides a practical way to fabricate parts and saves the cost and time which increases market competition. The molds with high precision and good surface roughness were duplicated by the rapid-prototype technique. Furthermore, this investigation demonstrates that: if the product contains special shapes? The material requires a large amount of cutting? or In the case of expensive and hard to machine materials, the proposed process is the best choice to duplicate cost-effective mold.