Calculations of internal stresses in the γ/γ′ microstructure of a nickel-base superalloy with high volume fraction of γ′-phase

1989 ◽  
Vol 23 (11) ◽  
pp. 1839-1844 ◽  
Author(s):  
U. Glatzel ◽  
M. Feller-Kniepmeier
Keyword(s):  
Volume Fraction ◽  
High Volume ◽  
High Volume Fraction ◽  
Internal Stresses ◽  
Nickel Base Superalloy ◽  
Nickel Base ◽  
Base Superalloy

Temperature dependence of deformation mechanisms in a single crystal nickel-base alloy with high volume fraction of γ′ phase

1996 ◽  
Vol 44 (6) ◽  
pp. 2397-2407 ◽  
Author(s):  
M. Feller-Kniepmeier ◽  
T. Link ◽  
I. Poschmann ◽  
G. Scheunemann-Frerker ◽  
C. Schulze
Keyword(s):  
Single Crystal ◽  
Temperature Dependence ◽  
Volume Fraction ◽  
Base Alloy ◽  
High Volume ◽  
High Volume Fraction ◽  
Deformation Mechanisms ◽  
Nickel Base Alloy ◽  
Nickel Base

Effect of Long-Term Aging on Microstructural Restoration in Cast Nickel Base Superalloy, GTD-111

2017 ◽  
Vol 891 ◽  
pp. 426-432 ◽  
Author(s):  
Chuleeporn Paa-Rai ◽  
J. Norachan ◽  
Panyawat Wangyao ◽  
Sureerat Polsilapa ◽  
Gobboon Lothongkum
Keyword(s):  
Aging Time ◽  
Research Study ◽  
Volume Fraction ◽  
Area Fraction ◽  
Nickel Base Superalloy ◽  
Final Microstructure ◽  
Reheat Treatment ◽  
Nickel Base ◽  
Base Superalloy

In this research study, the effect of long-term aging after various solutioning temperatures on final microstructure was investigated. The cast nickel base superalloy, GTD-111, usually has standard reheat treatment as follows: solutioning treatment at 1448 - 1478 K for 7.2 ‑ 21.6 ks and aging at 1118 K for 86.4 ks. However, from previous research works, the density of γ՛ phase was not reached the optimum value. Therefore, extension of aging time was performed in the study from 90 to 180, 270, 360, 720, 1080 and 1440 ks in order to increase density or volume fraction of precipitating γ՛ particles. From the results, it was found that longer aging time provided higher values of both area fraction and size of γ՛ particles. However, increase in aging time resulted in the hardness decrease.

Effect of Alloying Elements on Volume Fraction of γ′ Phase in Power Metallurgy Nickel-Base Superalloy

2017 ◽  
Vol 898 ◽  
pp. 430-437 ◽  
Author(s):  
Yang Chen ◽  
Gao Feng Tian ◽  
Lei Zhou ◽  
Yue Wang ◽  
Guo Jun Ma ◽  
...  
Keyword(s):  
Linear Regression ◽  
Aging Temperature ◽  
Volume Fraction ◽  
Alloying Elements ◽  
Nickel Base Superalloy ◽  
Alloying Element ◽  
Empirical Formulas ◽  
Nickel Base ◽  
Base Superalloy ◽  
Effect Of Alloying

The effect of alloying elements on the volume fraction of γ′ phase at aging temperature was investigated. The results indicated the volume fraction of γ′ was mainly sensitive to Al, Ti, Nb, Ta, and Cr. Based on analyzing the chemical component and the volume fraction of γ′ phase of 20 kinds of nickel-base superalloys , a linear regression formula between the volume fraction of γ′ phase and alloying element content was established using Matlab software, and the formula was given as: Vγ′=21.06+5.76Al+0.41Co-0.95Cr+0.84Hf+2.15Nb+0.82Ta+3.06Ti, where the correlation coefficient r = 95.5%. This linear equation was more accurate compared with the three public empirical formulas.

scholarly journals Cooling Rate Dependent Morphology of the γ' Precipitates in Nickel-Base Superalloy Udimet 500

2011 ◽  
Vol 278 ◽  
pp. 108-113 ◽  
Author(s):  
Mohammad Khalili Savadkoohi ◽  
Ahad Samadi ◽  
Rasoul Salehi
Keyword(s):  
Cooling Rate ◽  
Volume Fraction ◽  
Nickel Base Superalloy ◽  
Air Cooling ◽  
X Ray Diffraction ◽  
X Ray ◽  
Rate Dependent ◽  
Compositional Changes ◽  
Nickel Base ◽  
Base Superalloy

The morphology of the γ΄ precipitates during continues cooling of a nickel-base superalloy, Udimet 500, was studied using scanning electron microscopy and X-ray diffraction technique. The samples were full solutioned at 1200oC and then were cooled to ambient temperature under different cooling rates, 15, 1, 0.2, 0.05oC/min and air cooling. The unconstrained γ-γ΄ misfit values for each sample were calculated using the electrolytic extracted γ΄ precipitates. According to the results, by decreasing the cooling rate, not only the size, volume fraction and interparticle spaces of the  precipitates were increased, but also depending on the γ-γ΄ lattice misfits the corresponding  morphology was changed from spherical to cubic, then flower-like and finally dendritic shape. The observations are discussed in view of the compositional changes of γ/γ΄ phases and elastic strain considerations of their interfaces which will be described in detail in the article.

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