Discipline: Technology and Engineering
Subcategory: Civil/Mechanical/Manufacturing Engineering
Norman A. Burgos-León - University of Puerto Rico at Mayagüez
Co-Author(s): Oscar Marcelo Suárez, University of Puerto Rico at Mayagüez, PR.
Aerospace components bearing innovative and reliable weld fillers are critical in manufacturing lightweight and cost-effective structures for space exploration missions. Aluminum alloys are the filler of choice for such exacting applications, AA5356 being the most used alloy. These fillers, however, have a high fabrication cost due to the many alloying elements needed and the post-welding treatments the component must undergo to render optimum mechanical properties. Hence, to address these shortfalls, the use of nanoparticles, such as niobium diboride, has been proposed. These diboride particles have shown to enhance the fillers’ mechanical strength, providing higher service temperature and strength, wear resistance, and hardness, when compared to unreinforced fillers. Furthermore, we hypothesize that an addition of 4% magnesium, along with niobium diboride, will guarantee better-welded, AA6xxx-based alloys able to withstand extreme conditions typically encountered during space exploration. This study focuses on developing and optimizing the proposed novel aluminum/magnesium-based filler reinforced with niobium diboride nanoparticles for the development of multifunctional aerospace structures that can assure mission safety and success. To test this hypothesis, we manufactured NbB2 nanoparticles by fragmenting NbB2 pieces in a high energy ball mill to produce nanocomposite pellets (Al/NbB2) via cold welding. The pellets were then inoculated into molten Al-Mg alloys through stir casting, leading to a simple, inexpensive, and reproducible means of fabrication. Preliminary mechanical test results (i.e., tensile tests and Vickers hardness) on aluminum welds with nanoparticle-reinforced fillers showed an improvement of up to 40% when compared to unreinforced welds. The novel filler also exhibited enhanced castability, reduced leakage rates, and improved productivity and weld quality. These findings evinced that the said reinforcing nanoparticles enhance the mechanical properties of the welds, to ultimately render more reliable components capable of withstanding extreme space conditions, at an affordable cost. Further research will include conducting thermal analysis to study the solidification process of the weld and formulating a finite element model to simulate the welding behavior and failure modes.References: D. Florián, R. Marrero, X. Li, H. Choi, and O. M. Suárez, “Strengthening of Aluminum Wires Treated with A206/Alumina Nanocomposites,” Mater. (Basel, Switzerland), vol. 11, no. 3, p. 413, Mar. 2018.M. Fattahi, A. R. Gholami, E. Ahmadi, and S. Akhavan, “Improved microstructure and mechanical properties in gas tungsten arc welded aluminum joints by using graphene nanosheets/aluminum composite filler wires,” Micron., vol. 64, pp. 20–27, Mar. 2014.O. Suárez, J. Vazquez, and L. Reyes, “Synthesis and Characterization of Mechanically Alloyed Al/AlxMg1-xB2 Composites,” Sci. Eng. Compos. Mater., vol. 16, no. 4, pp. 267–276, 2009.
Funder Acknowledgement(s): Funder Acknowledgement(s): This material is based upon work supported by NSF under Grant No. 1345156 (CREST program). Also, this study was support, in part, by PR Space Grant Consortium, NASA Cooperative Agreement 80NSSC20M0052.
Faculty Advisor: Oscar Marcelo Suárez, firstname.lastname@example.org
Role: This Project was created for the purpose of preparing a doctoral thesis. I’ve worked on all aspects of this, starting with the elaboration and formulation of the problem and solution, along with my advisor. And all experimental work such as synthesis and characterization of nanoparticles and nanocomposites, manufacturing of the material (weld filler), and the welding process. In addition to other processes that are being worked on, such as finite element model to simulate the welding behavior.