Study of the influence of cobalt in the high formability of the Au-Fe system
Keywords:metallurgy, gold alloys, as-cast, heat-treatment, jewelry
Since ancient times, gold has been used due to its especial properties. Among those properties are the resistance to corrosion (for being noble), its high electrical and thermal conductivity, and also its conspicuous coloration. Gold has been applied in a diversity of subjects such as economy, jewelry, electronic circuits and odontology. The fascinating properties of gold are likely to improve with the preparation of alloys; among those, the Au-Fe alloys constitute some of the most studied nowadays. In this research, we present our results concerning the microstructure of the Au-Fe and Au-Fe-Co alloys. We fabricated gold based alloys with 25% (weight) Fe and then compared their structure and formability to Au-24.5Fe-0.5Co (% weight) to determine the role of cobalt in the alloy. An induction furnace with controlled atmosphere (argon) and conductor crucibles coated with zirconium silicate was used. The samples were characterized by three processes: as-cast, with heat treatment (HT) at T=900°C (1h and 3h) and as-cast centrifuged.
C. Lee, S. Kim, D. Lee, and R. Fukamichi, “Aging effects on microstructure and gmr in au-co and au-co-x x=cu,ni,fe bulk alloys,” IEEE Transactions on Magnetics, vol. 35, no. 5, pp. 2856–2858, Sept 1999.
Handbook of Alloy Phase diagram, 3rd ed., ASM International, Materials Park, Ohio, 1992.
E.Bosco, P.Rizzi, and M.Baricco, “Phase transformations in au–fe melt spun alloys,” Materials Science and Engineering: A, vol. 375–377, pp. 468–472, Jul 2004.
A.Blachowski, K.Ruebenbauer, J.Przewoźnik, and J.Żukrowskib, “Hyperfine interactions on iron nuclei in the bcc and fractally decomposed bcc/fcc mixed phase iron–gold alloys,” Journal of Alloys and Compounds, vol. 458, no. 1-2, pp. 96–103, Jun 2008.
A. Blachowski, K. Ruebenbauer, A. Rakowska, and S. Kąc, “Fractal-like behavior of the bcc/fcc phase separation in the iron-gold alloys,” Journal of Microscopy, vol. 237, no. 3, pp. 395––398, Apr 2010.
J. Fischer, “Hardening of low-alloyed gold,” Journal Gold Bulletin, vol. 38, no. 3, pp. 120––131, Sep 2005.
R. Süss, E. van der Lingen, L. Glaner, and M. du Toit, “18 carat yellow gold alloys with increased hardness,” Gold Bulletin, vol. 37, no. 3-4, pp. 196–207, Sep 2004.
C. Cretu and E. van der Lingen, “Coloured gold alloys,” Gold Bulletin, vol. 32, no. 4, pp. 115––126, Dec 1999.
Standard Test Methods for Determination of Gold in Bullion by Fire Assay Cupellation Analysis, American Society for Testing Materials, 2008.
S. M. Restrepo, A. I. Echavarría, M. A.Giraldo, J. A. Calderón, and H. D. Sánchez, “Colour evolution of the oxide layer formed on the au-25fe and au-24.5fe-0.5co,” Revista Facultad de Ingeniería, Universidad de Antioquia, no. 78, pp. 62–68, Mar 2016.
How to Cite
Copyright (c) 2018 Revista Facultad de Ingeniería Universidad de Antioquia
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Revista Facultad de Ingeniería, Universidad de Antioquia is licensed under the Creative Commons Attribution BY-NC-SA 4.0 license. https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en
You are free to:
Share — copy and redistribute the material in any medium or format
Adapt — remix, transform, and build upon the material
Under the following terms:
Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
NonCommercial — You may not use the material for commercial purposes.
ShareAlike — If you remix, transform, or build upon the material, you must distribute your contributions under the same license as the original.
The material published in the journal can be distributed, copied and exhibited by third parties if the respective credits are given to the journal. No commercial benefit can be obtained and derivative works must be under the same license terms as the original work.