Flow behavior and microstructural investigation of GTD 111 cast nickel base superalloy during hot pressure test

Subject Areas : journal of New Materials

مهسا Mohammadpour ¹ (materials engineering, hamedan university of technology, hamedan, iran)
امیر Momeni ² (materials engineering, hamedan university of technology, hamedan, iran)

Received: 2017-06-13 Accepted : 2018-05-08 Published : 2018-04-21

Keywords: Activation energy, GTD-111, superalloy, hot compression,

Abstract :

To investigate the behavior of the superalloy deformation behavior of GTD 111 casting, the hot-pressure tests were carried out at a temperature range of  950 -1100 ° C and strain rates of 1- 0.001 s^-1. All of the flow curves showed a relatively linear tension increase to one peak point and then its descent to a strain of 0.5, and the region of steady state deformation with constant stress was not observed. This process was attributed to the control of dislocations by the dendritic structure and their amplification at peak point. Microstructural investigations showed that the hot work would break the structure of the dendritic network and create separate cells. An increase in the temperature of the hot work, resulted an increase in the decomposition of the structure and the achievement of larger cells coused by dissolution of broken dendritic particles. Also, with the increase in the rate of deformation at a given temperature, the decomposition rate of the dendritic network decreased and its elongation increased in the direction of the deformation. Using the fundamental  constants of material, n, b and a were determined at the peak point. Also, with the help of the fundamental relationship of sinuses  hyperbolic, the amount of activation energy at the peak and the strain of 0.4 samples was 947 kJ / mol and 890 kJ / mol, respectively. These results showed that the deformation activation energy decreases with increasing strain and breaking the dendritic structure into distinct cells.

References:

1- M. Donachie & S. Donachie, ''Superalloys: a technical guide", ASM International, 2002.

 2- S.A. Sajjadi, S. Nategh & R. Guthrie, "Study of microstructure and mechanical properties of high performance Ni-base superalloy GTD-111", Materials Science and Engineering A325, 2002.

3- J. Mitchel, "Polycrystalline Nickel-Based Superalloys: Processing, Performance, and Application", Encyclopedia of Aerospace Engineering, 2010.

 4- A.K. Bhambri, T.Z. Kattamis & J.E. Morral, "Cast microstructure of Inconel 713C and its dependence on solidification variables", Metall. Trans. B 6B, 1975.

 5- J.F. Radavich, ''Microstructural and mechanical property characterization of aged Inconel alloy 625LCF", The Minerals, Metals &Materials Society, Technical Report, Micro-Met Laboratories, Inc.,West Lafayette, 1997.

 6- H.E. Collins, "Relative Long-Time Stability of Carbide and Intermetallic Phases in Nickel Base Superalloys", Trans. ASM 62, 1969.

 7- J.R. Mihalisin, G.G. Biever & R.T. Grant, Trans. TMS–AIME 242, 1968.

 8- S.A. Sajjadi, S. M. Zebarjad, R.I.L. Guthrie & M. Isac, "Microstructure evolution of high-performance Ni-Base superalloy GTD-111 with heat treatment parameters", 3rd congress of Iranian

  Society of Metallurgical Eng., Isfahan Uni. Of  Technology, Isfahan, Iran, Sept. 1999.

 9- A. Turazi, C. Augusto, C. Enrique & F. Comeli,  "Study of GTD-111 superalloy microstructural evolution during high-temperature aging and after rejuvenation treatments", Metallogr. Microstruct. Anal., 2015.

 10- C.T. Sims & W.C. Hagel, "The Superalloys I", John Wiley & Sons, NY,1972.

 11- C.T. Sims & E.W. Ross, "Superalloy II", John Wiley & Sons,1987.

 12- A.K. Ray, S.R. Singh, J. Swaminathan & P.K. Roy, "Structure property correlation study of a service exposed first stage turbine blade in a power plant", Materials Science and Engineering: A, Vol. 419, No. 1-2, 2006.

 13- Z. Huda, Development of heat-treatment process for a P/M superalloy for turbine blades, Mater. Design, 28, No. 5, 2007.

 14- F. Kang, J. Sun, G. Zhang & Z. Li, "Hot Deformation Characteristics for a Nickel-base Superalloy GH742y", J. Mater. Sci. Technol., Vol.25 No.3, 2009.      

15- Y.Q.Ning, T.Wang, M.W.Fu, M.Z.Li, L.Wang & C.D.Zhao, "Competition between work-hardening effect and dynamic-softening behavior for processing as-cast GH4720Li superalloys with original dendrite microstructure during moderate-speed hot compression", Materials Science&EngineeringA642, 2015.

 16- A. Nowotnik, J. Sieniawski & G. Mrówka-Nowotnik, Identification of dynamically precipitated phases in hot-working Inconel 718 alloy, Journal of Achievements in Materials and Manufacturing Engineering, VOLUME 31, ISSUE 2, December 2008.

17- G. Mrowka, A. Nowotnik, P. Rokichi & J.Sieniawski, "Dynamic Precipitation Of  Nickel Base Superalloys Undergoing Sever Diformation Below The Solvus Temprature", International Journal Of  Materials Research, Volume 106, July 2015.

18- J.S. Hou, J.T. Guo, L.Z. Zhou, C.Yuan & H.Q. Ye, "Microstructure and mechanical properties of cast Ni-base superalloy K44", Materials Science and Engineering A 374, 2004.

19-M. R. Jahangiri, S. M. A. Boutorabi & H. Arabi, ''Study on incipient melting in cast Ni base IN939 superalloy during solution annealing and its effect on hot workability'', Materials Science and Technology, VOL 28, NO 12, 2012.

20- EI Poliak & JJ Jonas, "A one-parameter approach to determining the critical conditions for the initiation of dynamic recrystallization'', Acta Materialia, Volume 44, Issue 1, Pages 127-136, 1996.

21- B.Zhang, L. Z.  Mengfei Li, W. Shen & S. Gu, ''Effects of microstructure and g¢ distribution on the hot deformation behavior for a powder metallurgy superalloy FGH96'', J. Mater. Res., Vol. 29, No. 23, Dec 14, 2014.

22- A.Nowotnik, P. Rokichi, G. Mrowka & J.Sieniawski, "Dynamic Precipitation Of  Nickel Base Superalloys Undergoing Sever Diformation Below The Solvus Temprature", International Journal Of  Materials Research, Volume 106, July 2015.

23- H. Zhang, C Li, Y. Liun, Q. Guo & H. Li, "Precipitation behavior during high-temperature isothermal compressive deformation of Inconel 718 alloy", Material Science & Engineering, A677, 2016.

 24- D. A. Porter, Phase Transformations in Metals and Alloys, Feb10, 2009.          

25- Y. Ning, Z. Yao, M.W. Fub & H. Guo, "Recrystallization of the hot isostatic pressed nickel-base superalloy FGH4096:I. Microstructure and mechanism", Materials Science and Engineering A 528 , 2011.

26- J.J. Jonas, C.M. Sellars & W.J. McGTegart,  "Strength and structure hot-working conditions", Rev. 14 (1), 1969.

 27- G.E. Dieter, "Mechanical metallurgy, New York", McGraw-Hill, 1961.

 28- A. Momeni, S.M. Abbasi, M. Morakabati & H. Badri, "A comparative study on the hot working behavior of inconel 718 and ALLVAC 718 Plus", Met. Mater. Trans.2017.

 29- B .Zhang, L. Z.  Mengfei Li, W. Shen & S. Gu, ''Effects of microstructure and g¢ distribution on the hot deformation behavior for a powder metallurgy superalloy FGH96'', J. Mater. Res., Vol. 29, No. 23, Dec 14, 2014