| Abstract Scope |
Investment casting (IC) is one of the oldest and most extensively used manufacturing processes for metals, where expendable wax patterns are transferred into metal casting. IC can produce precise and complex castings; despite this, it has limitations in large, complex, and thin castings. Along with this, the cost of the wax pattern and its dewaxing makes the IC costlier. Lost Foam Casting (LFC) overcomes these issues because of its ability to produce large near-net-shape complex castings, cheaper and lighter pattern material, and environmental friendliness. Worldwide, conventional foundries are adopting LFC technology. Lost foam foundries uses Expanded Polystyrene (EPS) foam as a pattern material which uses the molding route for pattern making. The molding route of pattern-making limits the LFC applications for mass production because of the high initial die cost and relatively less complex castings because of the manufacturability of the die. To address these difficulties, this article presents the Rapid Foam Foundry (RFF) concept, which is the synergic integration of the hybrid Foam Additive Manufacturing (FAM) machine into conventional foam foundry. In this article, the idea of "CAD to Cast" has been introduced the field of foam casting. The indigenously developed hybrid FAM machine has unique kinematics and a novel slicing approach. It realizes the part through one additive (gluing) and two subtractive (hot wire slicing and machining) processes. A Hybrid FAM machine will be add on to the conventional foam foundries, which will enhance the capacity of the conventional foam foundries by its ability to produce more complex patterns, which will be difficult to manufacture using the molding route. And it has the great potential to manufacture patterns for batch production and for a few specific parts. The present article also includes a lab-scale case study to prove the concept of RFF. In the Lab-scale case study, we created the EPS foam pattern through a hybrid FAM machine, and that foam pattern was transferred into the shell through the foam evaporation at 2500C for 15 min, followed by shell firing has been performed at 7500C for 1hr. Finally, the casting has been manufactured by pouring the LM6 aluminum alloy. Visual inspection shows no surface-casting defects. The 18µm and 25µm surface roughness has been recorded on the flat surface of the casting and foam pattern. |