Indian Welding Journal

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Vacuum Brazing of Inconel 718 to Ti-6Al-4V


Affiliations
1 Centre for Advanced Systems, DRDO, Yadgarpalli (V), Keesar (M), Hyderabad – 501301, Telangana, India
     

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The classic alloy Ti-6Al-4V is used in compression section of the turbine engine such as blades, discs and wheels. The turbine discs are amongst the most critical of components in the aeroengine and Inconel 718 is most widely used candidate alloy for these parts because of its excellent corrosion resistance, oxidation resistance, good tensile and creep properties at elevated temperatures. Fusion welding, as well as solid state welding processes of these dissimilar material combinations, result in formation of brittle intermetallic phases Ti2 Ni, TiNi3 and TiNi. The precipitation of undesirable phases such as intermetallic compounds and carbides causes a drastic deterioration in performance of the joints.

Vacuum brazing is one of the most promising routes to join dissimilar metallurgically incompatible materials. The mere fact is that brazing does not involve any substantial melting of the base materials, offers several advantages over other welding processes. The present work is an effort to understand the brazing aspects of Inconel 718 and Ti-6Al-4V, brazed at 950ºC in a high temperature vacuum furnace using Ti15Cu15Ni (wt%) brazing filler.

Vacuum brazing was successfully performed between Inconel 718 and Ti-6Al-4V. The microstructure and phases present in the bonded joints were analyzed by means of Optical Metallography, Scanning Electron Microscope, Energy Dispersive Spectrometer analysis and Electron Micro Probe Analysis. Tensile lap-shear strength of brazed joints were evaluated in the as-brazed condition. A maximum of 84 MPa and a minimum of 47 MPa strength was achieved in the brazed joints.


Keywords

Ti-6al-4v, Inconel 718, Vacuum Brazing, TiCuNi, Dissimilar Joint.
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  • Gerd L. and Williams J.C. (2007); Titanium, 2nd Ed., Springer.

  • Leyens C., and Peters M. (2003);Titanium and Titanium Alloys: Fundamentals and its applications, Wiley–VCH, GmbH & Co. KGaA.

  • Polmear I. J., (2006); Light Alloys- From Traditional Alloys to Nanocrystals, 4th Ed., Elsevier.

  • Reed R.C. (2006): The superalloys: Fundamentals and Applications, Cambridge University Press.

  • Eiselstein H. L., (1962); Age-hardenable nickel alloy. U.S. patent 3046108.

  • Prager M., and Shira C.S. (1968); Welding of Precipitation-Hardening Nickel-Base Alloys, Welding Research Council Bulletin No. 128.

  • Duvall, D. S. and Owczarski W.A. (1969); Studies of Postweld Heat-Treatment Cracking in Nickel-Base Alloys, Welding Journal, 48, pp.10s-22s.

  • Baker, H., (1992); ASM Handbook: Alloy Phase Diagrams, 10th Ed., ASM International, Materials Park, OH.

  • Bomberger H. B. (1969); personal correspondence, Reactive Metals, Inc., July, pp.17.

  • Cross W.B., Kuriotis A.H. and Stimler F.J., Nitinol characterization, NASA document number CR-1433, September, 1969.

  • Seretsky J., and Ryba E.R. (1976); Laser welding of dissimilar metals: Titanium to nickel, Welding Journal, July, pp.208s – 211s.

  • Fuji A., Horiuchi Y. and Yamamoto K. (2005); Friction welding of pure titanium and pure nickel, Science and Welding of Welding and joining, 10, pp.287 – 294.

  • Chatterjee S., Abinandanan T.A. and Chattopadhyay K. (2006); Microstructure development during dissimilar welding: Case of laser welding of Ti with Ni involving intermetallic phase formation, Journal of Materials Science, 41, pp.643 – 652.

  • Chiozzi S., Dattoma V. and Panella F. (2007); Capacitor discharge welded bars of Inconel 718 and Ti-6Al-4V superalloys under fatigue, Materials and Design,.

  • Sree Vardhan L. and Madhusudhan Reddy G. (2010); Friction welding of Ti-6Al-4V and Inconel 718, NMDATM, IISc Bangalore, India, November.

  • http://www.wesgometals.com

  • Department of Defence Handbook (2003): Metallic materials and elements for aerospace vehicle structures.

  • He P., and Liu D. (2006); Mechanism of forming interfacial intermetallic compounds at interface for solid state diffusion bonding of dissimilar materials, Materials Science and Engineering A, 437, pp.430 – 435.

  • Yao W., Wu A., Guisheng Z. and Jialie R. (2008); Formation process of the bonding joint in Ti/Al diffusion brazing, Materials Science and Engineering A, 480, pp.456 – 463.

  • Fournelle, R. A. (1979); Discontinuous Coarsening of Lamellar Cellular Precipitates in an Austenitic Fe-30Ni6Ti Alloy, ActaMetallurgica, 27, pp.1135–1145.

  • Liaw D.W., Wu Z. Y., Shiue R. K. and Chang C. S. (2007); Infrared vacuum brazing of Ti-6Al-4V and Nb using the Ti15Cu15Ni foil, Materials Science and Engineering A, pp.454 – 455, pp.104 – 113.

  • Chang C.T., Du Y.C., Shiue R.K. and Chang C.S. (2006); Materials Science and Engineering, 420A, pp.155 – 154.

  • Sam S., Kundu S. and Chatterjee S. (2012); Diffusion bonding of titanium alloy to micro-duplex stainless steel using a nickel alloy interlayer: Interface microstructure and strength properties, Materials and Design, 40, pp.237 – 244.

  • Villars P., Prince A. and Okamoto H. (1995); Handbook of Ternary Alloy Phase Diagrams, ASM International, Materials Park.

  • Neal D.F.(1981); Titanium'80, Science and Technology, p.1.


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  • Vacuum Brazing of Inconel 718 to Ti-6Al-4V

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Authors

Sree Vardhan Lalam
Centre for Advanced Systems, DRDO, Yadgarpalli (V), Keesar (M), Hyderabad – 501301, Telangana, India

Abstract


The classic alloy Ti-6Al-4V is used in compression section of the turbine engine such as blades, discs and wheels. The turbine discs are amongst the most critical of components in the aeroengine and Inconel 718 is most widely used candidate alloy for these parts because of its excellent corrosion resistance, oxidation resistance, good tensile and creep properties at elevated temperatures. Fusion welding, as well as solid state welding processes of these dissimilar material combinations, result in formation of brittle intermetallic phases Ti2 Ni, TiNi3 and TiNi. The precipitation of undesirable phases such as intermetallic compounds and carbides causes a drastic deterioration in performance of the joints.

Vacuum brazing is one of the most promising routes to join dissimilar metallurgically incompatible materials. The mere fact is that brazing does not involve any substantial melting of the base materials, offers several advantages over other welding processes. The present work is an effort to understand the brazing aspects of Inconel 718 and Ti-6Al-4V, brazed at 950ºC in a high temperature vacuum furnace using Ti15Cu15Ni (wt%) brazing filler.

Vacuum brazing was successfully performed between Inconel 718 and Ti-6Al-4V. The microstructure and phases present in the bonded joints were analyzed by means of Optical Metallography, Scanning Electron Microscope, Energy Dispersive Spectrometer analysis and Electron Micro Probe Analysis. Tensile lap-shear strength of brazed joints were evaluated in the as-brazed condition. A maximum of 84 MPa and a minimum of 47 MPa strength was achieved in the brazed joints.


Keywords


Ti-6al-4v, Inconel 718, Vacuum Brazing, TiCuNi, Dissimilar Joint.

References





DOI: https://doi.org/10.22486/iwj%2F2017%2Fv50%2Fi4%2F162274