Hybrid additive/substraction method for rapid casting prototypings with light-cured sand

Abstract

Developments in rapid casting technologies have led to a new era of inclusion of 3D printing. Rapid prototyping provides the flexibility and ease of reproducing a sand mold directly from CAD models, eliminating patterning steps, thus reducing the process time for creating prototypes. A novel hybrid technique, utilizing both additive and subtractive manufacturing techniques, has been developed and implemented. This technique finds applications in production of shaped cavities/molds for casted metallic parts for various rapid prototyping and rapid manufacturing application. The proposed concept of simultaneous building and machining of carbon shell sand molds for rapid prototyping (RP) of functional castings utilizes a combination of two RP techniques to eliminate the limitations of both. The proposed new hybrid RP technique based on previous research for developing of novel RP Infrared Light Sintering (IRS) and Machineable Mold Material (MMM) machining technologies. The IRS RP technique is used to build the molds layer by layer from 3D CAD models. The Machineable Mold Material process is utilized in machining of each layer before the next layer is built. The hybrid approach will combine the advantages of both methods to produce RP parts, quickly with high precision and surface finish. The extrusion system for the machineable mold material, machining parameters, and suitable machining tools has be tested and optimized. The outcome of this research will be the ability to produce functional casting prototypes of any size, complexity, and metal that could be mechanically and physically field tested and used as actual parts. To enhance practical research and learning experience of the students applying this hybrid technology, several undergraduate projects, master and Ph.D. allowed student to participate actively in the development of the processes. Numerous research presentation, papers and thesis was produced.