Additive Manufacturing of Syntactic Foams: Part 2: Specimen Printing and Mechanical Property Characterization
High-density polyethylene (HDPE) and its fly ash cenosphere-filled syntactic foam filaments have been recently developed. These filaments are used for three-dimensional (3D) printing using a commercial printer. The developed syntactic foam filament (HDPE40) contains 40 wt.% cenospheres in the HDPE matrix. Printing parameters for HDPE and HDPE40 were optimized for use in widely available commercial printers, and specimens were three-dimensionally (3D) printed for tensile testing at strain rate of 10−3 s−1. Process optimization resulted in smooth operation of the 3D printer without nozzle clogging or cenosphere fracture during the printing process. Characterization results revealed that the tensile modulus values of 3D-printed HDPE and HDPE40 specimens were higher than those of injection-molded specimens, while the tensile strength was comparable, but the fracture strain and density were lower.
Mrityunjay Doddamani acknowledges Department of Science and Technology, India, Grant DST/TSG/AMT/2015/394/G and Visiting Scientist Fellowship Grant VSP 17-7-001 by the U.S. Office of Naval Research—Global (program manager Dr. Ramesh Kolar) to visit NYU for this work. Nikhil Gupta acknowledges Office of Naval Research Grant N00014-10-1-0988. The views expressed in this article are those of the authors, not of funding agencies.