Abstract
Defect reduction is one of the most important goals in continuing research to improve remelting technologies, such as vacuum arc remelting, electroslag remelting, or hearth melting (plasma or electron beam), of specialty alloys. Ingot defects may originate from several sources in these processes, such as foreign materials in the melt stock or electrode, drop-in material from the furnace interior, and solidification defects. Laboratory-and industrial-scale melting experiments are used by Sandia National Laboratories and the Specialty Metals Processing Consortium to determine relationships between melt-processing conditions and defect formation. Examples described here include freckle formation, a solidification defect in large ingots of alloy 625 (electroslag remelting), and alloy 718 (vacuum arc remelting). These examples demonstrate how integrated melting experiments, process modeling, and ingot analysis can guide the control of melting conditions to reduce defects.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
L.A. Jackman, G.E. Maurer, and S. Widge, “White Spots in Superalloys,” Superalloys 718, 625, 706, and Various Derivatives, ed. E. Loria (Warrendale, PA: TMS, 1994), pp. 153–166.
B.K. Damkroger et al., “The Influence of VAR Processes and Parameters on White Spot Formation in Alloy 718,” Superalloys 718, 625, 706, and Various Derivatives, ed. E.A. Loria (Warrendale, PA: TMS, 1994), pp. 125–135.
L.A. Bertram et al., “The Macroscale Simulation of Remelting Processes,” JOM, 50 (3) (1998), pp. 18–21.
D.K. Melgaard, R.L. Williamson, and J. Beaman, “The Control of Remelting Processes for Superalloys and Aerospace Ti Alloys,” JOM, 50 (3) (1998), pp. 13–17.
J.S. Krafcik and J.A. Brocks, “Compositional Mapping of Large Samples Using X-Ray Fluorescence,” Conf. Proc. Development of Materials Characterization Technologies, ed. G. Vander Voort and J. Freil (Materials Park, OH: ASM, July 1995), pp. 111–118.
J.A. Brooks and J. Krafcik, “Metallurgical Analysis of a 520 mm Diameter Inconel 718 VAR Ingot,” Specialty Metals Processing Consortium Report, pp. 8–93.
P. Auburtin and A. Mitchell, “Elements of Determination of a Freckling Criterion,” Proceedings of Vacuum Metallurgy Conference, VMD/AVS (Pittsburgh, PA: AVS, 1997), pp. 18–34.
L.A. Jackman, G.E. Maurer, and S. Widge, “New Knowledge About ‘White Spots’ in Superalloys,” Advanced Materials and Processes, 5 (1993), pp. 18–25.
A.F. Gaimei and B.H. Kear, Metall. Trans. A, 1 (8) (1990), pp. 2185–2192.
D. Ablitzer et al., “Mathematical Modeling of Electron Beam Remelting Process, Application to the Processing of Titanium Alloys,” Electron Beam Melting and Refining State of the Art 1992, ed. R. Bakish (Reno, NV: Bakish Materials, 1992), pp. 85–91.
J.P. Bellot et al., “Dissolution of Hard-Alpha Defects Dragged in a Bath of Liquid Titanium,” Proceedings of Vacuum Metallurgy Conference, VMD/AVS (Pittsburgh, PA: AVS, 1994), pp. 155–166.
A. Powell, U. Pal, and J.A. Van Den Avyle, “Optimal Beam Pattern to Maximize Inclusion Residence Time in an Electron Beam Melting Hearth,” Proceedings of Vacuum Metallurgy Conference, VMD/AVS (Pittsburgh, PA: AVS, 1997), pp. 78–86.
R.G. Reddy, “Kinetics of TiN Dissolution in Ti Alloys,” Electron Beam Melting and Refining State of the Art 1990, ed. R. Bakish (Reno, NV: Bakish Materials, 1990), pp. 119–127.
Author information
Authors and Affiliations
Additional information
Editor’s Note: A hypertext-enhanced version of this article, including video of the arc gap during the vacuum remelting of alloy 718, can be found on the TMS web site at www.tms.org/pubs/journals/JOM/9803/VanDenAvyle-9803.html.
James A. Van Den Avyle earned his Ph.D. in metallurgical engineering at the Massachusetts Institute of Technology in 1975. He is currently a principal member of the technical staff at Sandia National Laboratories.
John A. Brooks earned his Ph.D. in metallurgy at Carnegie Mellon University in 1981. He is currently a principal member of the technical staff at Sandia National Laboratories. Dr. Brooks is also a member of TMS.
Adam C. Powell earned his Ph.D. in materials science and engineering from the Massachusetts Institute of Technology in 1997. He is currently a post-doctoral researcher in metallurgy at the National Institute of Standards and Technology. Dr. Powell is also a member of TMS.
Rights and permissions
About this article
Cite this article
Van Den Avyle, J.A., Brooks, J.A. & Powell, A.C. Reducing defects in remelting processes for high-performance alloys. JOM 50, 22–25 (1998). https://doi.org/10.1007/s11837-998-0374-7
Issue Date:
DOI: https://doi.org/10.1007/s11837-998-0374-7