Investigating the Cyclic Oxidation and Hot Corrosion of Nanostructured CoNiCrAlYSi Coatings Applied by HVOF Process

Subject Areas : journal of New Materials

A.H. Yaghtin ¹ , S. Javadpour ² , M.H. Shariat ³

1 - دانشجوی دکتری مهندسی مواد دانشگاه شیراز.
2 - استاد گروه مهندسی مواد داشگاه شیراز.
3 - استاد گروه مهندسی مواد داشگاه شیراز.

Received: 2016-01-30 Accepted : 2016-01-30 Published : 2016-01-21

Keywords: CoNiCrAlYSi, HVOF, Cryo Milling, cyclic Oxidation, Hot Corrosion,

Abstract :

In this research, cyclic oxidation and hot corrosion behavior of nanostructure CoNiCrAlYSi coatings, deposited by HVOF thermal spray process, have been investigated. To achieve nanosized particles, the initial CoNiCrAlYSi powder was cryomilled and then HVOF sprayed to form a nanostructure coating. The coating’s performance has been evaluated via cyclic oxidation and hot corrosion tests. Microstructure changes and phase analysis of the coatings during tests have been studied. The coatings endured on the substrate for 115 cycles and 700 hours during cyclic oxidation and hot corrosion tests, respectively. The increased lifetime of nanostructure coatings with respect to conventional coatings is attributed to some α-Al₂O₃ particles dispersed in the structure, created by cryomilling, and high-diffusivity paths as a result of nanocrystallization, which favors the formation of a continuous and protective α-Al₂O₃ barrier layer on the top of the coating.

References:

 

1-M.Hetmańczyk, L.Swadźba and B.Mendala, “Advanced Materials and Protective Coatings in Aero-engines application”, Journal of Achievements in Materials and Manufacturing Engineering, Vol. 24 (1), pp. 372-381, 2007.

2- M. J. Pomeroy, “Coatings for gas Turbine Materials and Long Terms Stability Issues”, Materials and Design, Vol. 26, pp. 223-231, 2005.

3- J. Wigren and L. Pejryd, “Thermal Barrier Coatings-Why, How, Where and Where to”, Proceedings of 15th International Thermal Spray Conference, Edited by Coddet, France, pp. 1531-1542, 1998.

4-K.Ma andJ. M. Schoenung, “Influence of Cryomilling on the Microstructural Features in HVOF-Sprayed NiCrAlY bond coats for Thermal Barrier Coatings: Creation of a Homogeneous Distribution of Nano Scaledispersoids”, Philosophical Magazine Letters, Vol. 90 (10), pp. 739–751, 2010.

 

5- T.A. Taylor and P.N. Walsh, “Thermal Expansion of MCrAlY Alloys”, Surface and Coatings Technology, Volumes 177–178,pp. 24-31, 2004.

6-K.Ma andJ. M. Schoenung, “Isothermal Oxidation Behavior of Cryomilled NiCrAlY Bond Coat: Homogeneity and Growth rate of TGO”, Surface & Coatings Technology, Vol. 205, pp.5178-5185, 2011.

7- A.G. Evans, D.R. Clarke and C.G. Levi, “The Influence of Oxides on the Performance of Advanced Gas Turbines”, Journal of the European Ceramic Society, Vol. 28, pp. 1405-1419, 2008.

8- A.G. Evans, D.R. Mumm, J.W. Hutchinson, G.H. Meier and F.S. Pettit, “Mechanisms Controlling the Durability of thermal Barrier Coatings”, Progress in Materials Science, Vol. 46, pp. 505-553, 2001.

9- D.Mercier, B. D.Gauntt andM.Brochu, “Thermal Stability and Oxidation Behavior of Nano Structured NiCoCrAlY Coatings”, Surface & Coatings Technology, Vol. 205, pp. 4162–4168, 2011.

10- H.Lou, F.Wang, S.Zhu, B.Xia andL. Zhang, “Oxide formation of K38G superalloy and its sputtered' micrograined coating”, Surface & Coatings Technology, Vol. 63, pp. 105-114, 1994.

11- Q. Zhang, C. J. Li, C. X. Li, G. J. Yang and S. C. Lui, “Study of oxidationbehavior of nanostructured NiCrAlY Bond Coatings Deposited by Cold Spraying”, Surface and Coatings Technology, Vol. 202, pp. 3378–3384, 2008.

12-F.Tang, L.Ajdelsztajn and J. M. Schoenung, “Influence of Cryomilling on the Morphologyand Composition of the Oxide Scales Formed on HVOF CoNiCrAlY Coatings,”Oxidation of Metals, Vol. 61, pp. 219-238, 2004.

13-L.Ajdelsztajn, J. A.Picas, G. E.Kim, F. L.Bastian, J.Schoenungand V.Provenzano, “Oxidation Behavior of HVOF sprayed Nano Crystalline NiCrAlY Powder”, Materials Science and Engineering A, Vol. 338, pp. 33-43, 2002.

14- J. A.Picas, A.Forn, L.Ajdelsztajn and J. Schoenung, “Nano CrystallineNiCrAlY powder Synthesis by Mechanical Cryomilling,” Powder Technology, Vol. 148, pp. 20–23, 2004.

15- K. E. Schneider, V. Belashchenko, M. Dratwinski, S. Siegmann and A. Zagorski, “Thermal Spray for Power Generation Components”, John Wiley & Sons, New York, 2008.

16-J.Stoke,“The Theory and Application of the HVOF Thermal Spray Process”, Dublin City University, 2008.

17-M.Mohammadi, S.Javadpour, A. Kobayashi, S. A.JenabaliJahromi andK.Shirvani, “Thermal shock properties and Microstructure Investigation of LVPS and HVOF-CoNiCrAlYSi Coatings on the IN738LC Superalloy”, Vacuum, Vol. 88, pp. 124-129, 2012.

18- M. Mohammadi, S. Javadpour, A. Kobayashi, S.A. JenabaliJahromi and K. Shirvani, “Thermal Shock Properties and Microstructure Investigation of LVPS and HVOF-CoNiCrAlYSi Coatings on the IN738LC Superalloy”, Vacuum, Vol. 88, pp. 124-129, 2013.

19- A.H. Yaghtin, S. Javadpour and M.H. Shariat, “Hot Corrosion of Nano Structured CoNiCrAlYSi Coatings Deposited by High Velocity Oxy Fuel Process”, Journal of Alloys and Compounds 584 , 303–307, 2014.