Study on Functionally Gradient Materials Under International Research Experiences for Undergraduates Program: US - South Africa Collaboration

Abstract

This paper details the ongoing research conducted by Milwaukee School of Engineering senior undergraduate students in South Africa under the third year of the Research Experiences for Undergraduates grant EEC-1460183 sponsored by the National Science Foundation (Principal Investigator Dr. Kumpaty). Andrew Gray and Kevin Sivak conducted research in summer of 2017 under advisement of Dr. Kumpaty and his South African collaborators, Dr. Esther Akinlabi, Dr. Mutiu Erinosho and Dr. Sisa Pityana. They extended the work of Paoli (reported in IMECE2017-71037), with varying percent of Mo (0–15%) in the combination of Ti64-Mo deposited on Ti64 substrate at laser powers of 1500 and 1700 W for a select scan speed. Laser metal deposition was completed at the CSIR – National Laser Center, in Pretoria, South Africa and the material characterization was performed at the University of Johannesburg as in the previous year. Hardness decreased with addition of Mo. Lowest hardness was observed in 10% Mo layers, and greater percent of Mo led some agglomeration issues due to its melting temperature being much higher than that of Ti64. Corrosion tests were also attempted. Etching challenges were present as percent of Mo varied in the same sample. Results are directly applicable to biomedical industry in evaluating functionally graded materials. An alumnus of MSOE, Peter Spyres served as a liaison for our international REU participants as he engaged them during the weekends in a cultural immersion which otherwise would not have been possible. Gray and Sivak were able to spend July 4th at the U.S. Consulate in Pretoria. While the research collaborators have generously provided support, it is the care taken by Peter’s remarkable household, which enhanced the beneficial value of this international research enterprise.