Multilayer characterization of Inconel-718 and Ni couples with Al in TLPB process

M. POLISERPI ; R. BOERI; C. POLETTI; S. SOMMADOSSI

Darmstadt

Congreso; Materials Science and Engineering; 2018

DGM Deutsche Gesellschaft für Materialkunde

Multilayer characterization of Inconel-718 and Ni couples with Al in TLPB processM. Poliserpi 1,2, R. Boeri 2, C. Poletti3, S. Sommadossi1*ssommadossi@comahue-conicet.gob.ar1 Materials Characterization, IITCI CONICET-UNCo, Neuquen, Argentina2 Metalurgy Division, INTEMA CONICET-UNMdP, Mar del Plata, Argentina3 IMAT, TU-Graz, Graz, Austria*SpeakerAbstractThe attractive properties of Al-Ni intermetallic phases and their extensive field oftechnological applications demands a thorough understanding of the system. The featuresof the Al-Ni system are the reason for the high-temperature strength of Ni-based superalloys (e.g. INCONEL-718), such as high thermal stability, high corrosion resistance andhigh strength to density ratio. The Transient Liquid Phase Bonding (TLPB) is a technologicalprocess which can be applied to manufacture new pieces and to perform reparations, whichdeals with the simultaneous growing of intermetallic phases as multilayers in theinterconnection zone. Ni-based super alloys also find application as protective coatings. Bymeans of optic and electronic microscopy (SEM/EDS/EBSD) and Vickers test, themicrostructure, composition profiles, growth kinetic and hardness of the Intermetallic Layers(ILs) were analyzed, especially focused on solid?solid interactions during isothermalannealing in reactive diffusion couples Ni/Al and Inconel/Al (800?1170 ºC). The study yieldsto association of the Al?Ni Intermetallic Phases (IPs) to the ILs, in particular two kind of NiAlphase. Martensitic transformation was also found in a Ni-rich IL at 1170 ºC. Theincorporation of additional elements to the binary intermetallics is also analyzed.Conventional X-Ray Diffraction (XRD) experiments complements the EBSD analyses of thecrystallographic study for the multilayer sequence in the interconnection zone.Keywords: INCONEL, Ni-Al, intermetallic layers, microstructure, TLPB, EBSDReferences:1. M. Pouranvari, A. Ekrami, A.H. Kokabi. Microstructure evolution mechanism duringpost-bond heat treatment of transient liquid phase bonded wrought IN718 superalloy:An approach to fabricate boride-free joints. Journal of Alloys and Compounds (2017)DOI: 10.1016/j.jallcom.2017.06.2062. J. N. Du Pont, J. Lippold, S. Kiser. Welding Metallurgy and Weldability of Nickel-baseAlloys, John Wiley & Sons (2009).3. Ding, Z., Hu, Q., Lu, W., Sun, S., Xia, M., & Li, J.. In situ observation on the formationof intermetallics compounds at the interface of liquid Al/solid Ni. Scripta Materialia,130 (2017) 214-218.4. G. W. Goward and D. H. Boone. Mechanisms of Formation of Diffusion AluminideCoatings on Nickel-Base Superalloys. Oxidation of Metals, Vol. 3, No. 5 (1971) 475-4955. Mehrer, H., Shoo, U., Hirscher, M., Growth of intermetallic phases and interdiffusionin the Al-Ni system. Defect and Diffusion Forum 143-147 (1997) 631-636.6. Miracle,D., The physical and mechanical properties of NiAl. Acta metall. mater. 41(1993) 649-684.7. Sommadossi, S., López, G.A., Zieba, P., Gust, W., Mittemeijer,E.J., Kineticbehaviour of diffusion-soldered Ni/Al/Ni interconnections. Mater. Chem. Phys. 78(2002), 459-463.8. Sommadossi, S., López, G.A., Zieba, P., Gust, W., Mittemeijer, E.J., Phasecharacterization of diffusion soldered Ni/Al/Ni interconnections. Interface Sci. 10(2002) 13-19.9. Sommadossi, S., Tumminello, S., Growth kinetics of intermetallic phases in transientliquid phase bonding process (TLPB) in Al /Ni system. Defect and Diffusion Forum323-5 (2012) 465-470.10. A. Urrutia, S. Tumminello, D. Lamas, S. Sommadossi. X-Ray Characterization ofIntermetallic Phases in Al/Ni Multilayer System. Procedia Materials Science 8 ( 2015)1150 ? 115911. Urrutia, A., Tumminello, S., Aricó, S.F., Sommadossi, S., Characterization of Al?Niintermetallics around 30?60 at% Al for TLPB application. CALPHAD: ComputerCoupling of Phase Diagrams and Thermochemistry 44 (2014) 108?113.