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Mechanical properties of uncoated and aluminide-coated rené 80

Rahmani, Kh ; Sharif University of Technology

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  1. Type of Document: Article
  2. DOI: 10.1007/s11661-009-0046-4
  3. Abstract:
  4. Nickel-base superalloys such as René 80 are widely used in manufacturing aircraft turbine blades. They are usually coated in order to increase their wear, oxidation, erosion, and hot corrosion properties against environmental degradation. In this article, the mechanical behavior (tensile and low-cycle fatigue (LCF)) of uncoated and aluminide-coated (CODEP-B) René 80 has been studied at 871 °C and 982 °C. Experimental results show that the tensile properties of coated specimens are relatively lower than those of uncoated ones in the same conditions, but application of coating increases the LCF life of René 80 at T = 871 °C, 982 °C, R = (εmin/εmax) = 0, strain rate of 2 × 10-3 s-1, and Δεt = 0.8 pct. Scanning electron microscopy (SEM) studies of coated specimens at N = Nf show that the nucleation of cracks occurs merely in substrate, but cracks start from the surfaces in uncoated specimens. Transmission electron microscopy (TEM) investigations have been performed on fractured uncoated specimens to evaluate the microstructures at different temperatures. The misfit dislocation, pair dislocations, and cutting of γ′ were observed at T = 871 °C and 982 °C. The TEM studies also showed that at 982 °C stacking fault was observed in γ′ particles
  5. Keywords:
  6. Aircraft turbines ; Aluminides ; Environmental degradation ; Hot corrosion properties ; Low cycle fatigues ; Mechanical behavior ; Misfit dislocations ; Nickel base superalloy ; SEM ; TEM ; Cracks ; Laser fusion ; Scanning electron microscopy ; Strain rate ; Transmission electron microscopy ; Turbomachine blades ; Mechanical properties
  7. Source: Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science ; Volume 41, Issue 1 , 2010 , Pages 125-137 ; 10735623 (ISSN)
  8. URL: http://link.springer.com/article/10.1007/s11661-009-0046-4