Scientific Research and Essays

  • Abbreviation: Sci. Res. Essays
  • Language: English
  • ISSN: 1992-2248
  • DOI: 10.5897/SRE
  • Start Year: 2006
  • Published Articles: 2750

Full Length Research Paper

High temperature oxidation behaviour of a Ni based superalloy produced by mechanical alloying

Mehmet ERDEM1* and Mehmet TURKER2
1Mechanical Engineering Department, Inonu University, Malatya, Turkey. 2Metallurgy and Material Engineering Department, Faculty of Technology, Gazi University, 06500, Teknikokullar, Ankara, Turkey.
Email: [email protected]

  •  Accepted: 23 July 2012
  •  Published: 10 December 2012

Abstract

In this study, Ni based superalloy powders (75% Ni, 20% Cr, 4% Al2O3, 0.6% Ti and 0.4% Y2O3), were mechanically alloyed for up to 8 h and were compacted and sintered at 1200°C. Sintered samples were hot-deformed at 1200°C for various amounts and secondary recrystallisation was applied at 1325°C for 1 h. Isothermal oxidation tests were conducted at 1000°C for up to 100 h in air. Surface morphology, fractured surface and chemical composition of the samples were analyzed by using x-ray diffraction (XRD) and scanning electron microscopy (SEM). Cr2O3 film formed on the surface of the samples after exposure in air. Weight change results indicated the samples gained a small weight by increasing the exposure time. All samples exhibited sub-parabolic oxidation behavior.

 

Key words: Mechanical alloying, powder metallurgy, oxidation, microstructure,superalloy.