Impact of gamma′ particle coarsening on the critical resolved shear stress of nickel-base superalloys with low aluminium and/or titanium content

• Published in: Journal of nuclear materials Vol. 416; no. 1; pp. 55 - 59
• Main Authors: Ispánovity, Péter Dusán, Bakó, Botond, Weygand, Daniel, Hoffelner, Wolfgang, Samaras, Maria
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.09.2011; Elsevier
• Subjects: Applied sciences; Controled nuclear fusion plants; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fission nuclear power plants; Fuels; Installations for energy generation and conversion: thermal and electrical energy; Nuclear fuels; Hardening; Statistical analysis; Mechanical properties; Titanium; Aluminium; Nickel; Nuclear reactor
• ISSN: 0022-3115; 1873-4820
• DOI: 10.1016/j.jnucmat.2010.11.051

In Ni-base superalloys with low Al and/or Ti content the precipitation and subsequent coarsening of γ′ particles at intermediate temperatures contribute to the degradation of the mechanical properties of the alloy. In the present paper the coarsening process is modelled and the change of the critical resolved shear stress of the alloy due to coarsening of the γ′ particles is calculated by means of statistical analysis of the depinning of a single gliding edge dislocation. It is found that the contribution of γ′ hardening to the critical resolved shear stress at 973 K reduces to more than half of its original value in less than one year.