Mechanical and material properties of castings produced via 3D printed molds

Additive manufacture of sand molds via binder jetting enables the casting of complex metal geometries. Various material systems have been created for 3D printing of sand molds; however, a formal study of the materials' effects on cast products has not yet been conducted. In this paper the authors investigate potential differences in material properties (microstructure, porosity, mechanical strength) of A356 - T6 castings resulting from two different commercially available 3D printing media. In addition, the material properties of cast products from traditional "no-bake" silica sand is used as a basis for comparison of castings produced by the 3D printed molds. It was determined that resultant castings yielded statistically equivalent results in four of the seven tests performed: dendrite arm spacing, porosity, surface roughness, and tensile strength and differed in sand tensile strength, hardness, and density.