Alternative Mold Material for Cast Magnesium Kari a. berna, Benjamin f. schultz Alternative Mold Material for Cast Magnesium

Alternative Mold Material for cast magnesium Objectives Develop a sintering procedure for a proprietary mold material Understand the thermal decomposition of volatile ingredients. Produce Test specimens for hardness measurement and evaluate their fracture.

Alternative Mold Material for cast magnesium BackRound Magnesium is notoriously difficult to cast, as it reacts with most refractory compounds that have been used in the 3d printing process. Despite this drawback, magnesium is an attractive material due to its light weight, good mechanical and damping properties, as well as its biodegradability. If successful, this new technology would allow for the production of custom magnesium prototypes and components for the transportation, aerospace, and biotechnology sectors.

Experimental Alternative Mold Material for cast magnesium Mixed paste material based on proprietary recipe. The mixture was then mixed with a residence acoustic mixer to produce a viscous paste-like substance. A simple mold was prepared to dry the paste at room temperature for 24 hours to create green preform. Two sintering processes were investigated. One simply drying at 150˚C, Two drying and sintering at 1000˚C.  Candidate binder materials for the paste were evaluated using Thermo-Gravimetric Analysis (TGA), including Guar Gum and Methylcellulose •Two sintering processes were evaluated using the Rockwell H Scale (1/8’ carbide ball indenter 60kg load).

Results Greater Hardness Pores Alternative Mold Material for cast magnesium Text Results TGA analysis showed that both candidate materials composed completely at 500˚C The sample heat treated at 1000˚C (Sample B) had a rockwell hardness of 157 HRH. The sample heat treated at 150˚C (Sample A) fractured during the measurement. Qualitatively, Sample B had a greater toughness than Sample A. Greater Hardness Pores

Alternative Mold Material for cast magnesium Text Conclusions Both candidate binder materials fully decompose at approximately 500˚C Candidate material two decomposes more slowly then candidate one. The material sintered at 150˚C was porous and extremely brittle where as the material sintered at 100˚C appeared to be less porous and have a greater strength.

Alternative Mold Material for cast magnesium Text Acknowledgments This work is founded by the UWM Research Foundation (B. F. Schultz, PI) and through the SURF program.