Rapid Prototyping for Casting Rapid Prototyping for Casting Aaron Agostino Mechanical Engineering – Union College Advisor – Professor Amy Hsiao, Ph.D

Background As villages were first forming there was a developing need for specialized objects. Agricultural equipment, tools, jewelry, and many other products became necessary, and investment casting was there to meet the demands. The techniques used two thousand years ago were nearly the same as those of today, though in the last hundred years our casting methods have been refined to meet the precision required of our society.

What I am trying to do Lost wax casting has been around since the Neolithic period and is what I am basing my project on, though rather than using wax, ABS prototypes are the starting medium. Because of my interest in metals and design, this project had some appeal to me when first suggested. Now that I am working on parts, the little problems that are coming up add to the motivation and make the project more rewarding. The primary goal is to get a better understanding of the casting process, while also trying new methods. If things go well, next term my project will move towards function by creating useful and intentional working parts as the process becomes more routine.

The Process ◦ Part conceptualized and created 3-dimensionally using SolidWorks ◦ Parts is sliced and exported as an.STL file to be dribbled on the rapid prototype machine ◦ Vents are created, dribbled, and adhered ◦ Mold is made around ABS part with a ceramic slurry ◦ Part is melted out of mold with torch ◦ Molten alloy is poured from crucible into warm mold to form part ◦ Mold is broken away leaving the part ◦ Vents and sprue are grinded off of the part, leaving the final product

Setup and Equipment Melting process to remove ABS part from ceramic mold (above) Oven, crucible, and tongs for casting process (below)

What has been done Part was built using SolidWorks (1) – Converted and sliced for the rapid prototyping machine which produced ABS part (2) – mold was poured around part – attempt was made to melt out part from ceramic mold (3) (1) (2) (3)

The Second Try Due to the difficulty of removing the ABS from the mold on the first attempt, the next part was designed to be geometrically more appropriate for removal What the part was built to look like (hollow) Mold after part is removed

National Educators Workshop in Materials Science and Engineering at NIST in Gaithersburg, MD My poster for the The research poster competition 

What Has Been Found Thus Far Main problems so far: Since the ABS doesn’t melt out as much as it burns, the geometry must be conducive to pulling out the softened parts from the mold Ceramic which is being used, primarily composed of silica powder, is very brittle at the temperatures necessary for the ABS melting Cu-Al needs 1085°C to liquefy, which is at the top of the range for the ovens available (1100 °C ), which creates a hesitance to push the ovens so hard

Still to Come Still to do this term: -Pour another part before break -Update website ( antipasto.union.edu/~agostina) Next term: - Molds of different ceramic materials - Casting with other material compositions - Create more complicated parts that serve a predefined purpose

Questions about project? Acknowledgements Professor Hsiao - Stan Gorski - Rhonda Becker