scholarly journals The Importance of Diffusivity and Partitioning Behavior of Solid Solution Strengthening Elements for the High Temperature Creep Strength of Ni-Base Superalloys

2020 ◽  
Vol 51 (12) ◽  
pp. 6195-6206 ◽  
Author(s):  
S. Giese ◽  
A. Bezold ◽  
M. Pröbstle ◽  
A. Heckl ◽  
S. Neumeier ◽  
...  
Keyword(s):  
Solid Solution ◽  
High Temperature ◽  
Creep Resistance ◽  
Elevated Temperatures ◽  
Solid Solution Hardening ◽  
Stress Regime ◽  
Solid Solution Strengthening ◽  
Solution Strengthening ◽  
The Individual ◽  
Partitioning Behavior

AbstractThe creep resistance of single-crystalline Ni-base superalloys at elevated temperatures depends among others on solid solution strengthening of the γ-matrix. To study the influence of various solid solution strengtheners on the mechanical properties, a series of Ni-base superalloys with the same content of different alloying elements (Ir, Mo, Re, Rh, Ru, W) or element combinations (MoW, ReMo, ReW) was investigated. Nanoindentation measurements were performed to correlate the partitioning behavior of the solid solution strengtheners with the hardness of the individual phases. The lowest γ′/γ-hardness ratio was observed for the Re-containing alloy with the strongest partitioning of Re to the γ-matrix. As a result of the creep experiments in the high-temperature/low-stress regime (1373 K (1100 °C)/140 MPa), it can be concluded that solid solution hardening in the γ-phase plays an essential role. The stronger the partitioning to the γ-phase and the lower the interdiffusion coefficient of the alloying element, the better the creep resistance. Therefore, the best creep behavior is found for alloys containing high contents of slow-diffusing elements that partition preferably to the γ-phase, particularly Re followed by W and Mo.

Understanding solid solution strengthening at elevated temperatures in a creep-resistant Mg–Gd–Ca alloy

2019 ◽  
Vol 181 ◽  
pp. 185-199 ◽  
Author(s):  
Ning Mo ◽  
Ingrid McCarroll ◽  
Qiyang Tan ◽  
Anna Ceguerra ◽  
Ying Liu ◽  
...  
Keyword(s):  
Solid Solution ◽  
Elevated Temperatures ◽  
Solid Solution Strengthening ◽  
Solution Strengthening

Mechanical Properties of Ga1–xInxAs

1985 ◽  
Vol 53 ◽  
Author(s):  
S. Guruswamy ◽  
J.P. Hirth ◽  
K.T. Faber
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
High Temperature ◽  
Strengthening Effect ◽  
Plateau Stress ◽  
Solid Solution Strengthening ◽  
Stress Region ◽  
Solution Strengthening ◽  
Concentration Levels ◽  
Undoped Gaas

ABSTRACTSubstantial solid solution strengthening of GaAs by In acting as InAs4 units has recently been predicted. This strengthening could account for the reduction of dislocation density in GaAs single crystals grown from the melt. High temperature hardness measurements up to 700ºC have been carried out on (100) GaAs and Ga0.9975 In0.0025 As wafers. Results show a significant strengthening effect in In—doped GaAs even at concentration levels of about 0.2 wt%. A temperature independent flow stress region is observed for both these alloys. The In—doped GaAs shows ahigher plateau stress level compared to the undoped GaAs. The results are consistent with the solid solution strengthening model.

Nanoindentation investigations to study solid solution hardening in Ni-based diffusion couples

2009 ◽  
Vol 24 (3) ◽  
pp. 1127-1134 ◽  
Author(s):  
Oliver Franke ◽  
Karsten Durst ◽  
Mathias Göken
Keyword(s):  
Solid Solution ◽  
Solid Solution Hardening ◽  
Diffusion Couples ◽  
Indentation Size ◽  
Careful Evaluation ◽  
Solution Hardening ◽  
Solid Solution Strengthening ◽  
Acta Mater ◽  
Solution Strengthening

In this work the hardening effect of Ta and Mo in Ni-base alloys was investigated using a combinatorial approach with diffusion couples. Furthermore, the Ni-Fe system was used as a reference system taking advantage of the full miscibility at high temperatures. Ta was chosen, as aside from having a technical relevance in the Ni-base superalloys, it also has a high miscibility in Ni. The main focus of this paper will be solid solution hardening. It will be shown that even though the determination of hardness is subject to varying indentation size effects (ISE) [Durst et al., Acta Mater.55(20), 6825 (2007)], only a few modifications are necessary to describe solid solution strengthening measured by nanoindentations using the Labusch theory [Labusch, Acta Metall.20(7), 917 (1972)]. Moreover, after a careful evaluation of the results, the data can be used to investigate solid solution hardening effects quickly and efficiently with small amounts of material.

Modelling of the Influence of Laves Phase on the Creep Properties in 9% Cr Steels

2007 ◽  
Author(s):  
Hans Magnusson ◽  
Rolf Sandstro¨m
Keyword(s):  
Solid Solution ◽  
Creep Strength ◽  
Solute Drag ◽  
Laves Phase ◽  
Solid Solution Hardening ◽  
Moving Frame ◽  
Creep Properties ◽  
Solid Solution Strengthening ◽  
Solution Strengthening ◽  
Multi Component System

Nucleation and growth of Laves phase are calculated for a multi-component system. Coarsening of MX, M23C6 and Laves are also determined. The influence on creep strength is discussed by analysing particle hardening and solid solution strengthening. A model for particle size distribution is presented in order to determine the amount of dislocations that can climb across particles or generate Orowan loops. The model for solid solution hardening is based on a solution of Fick’s second law with a moving frame of reference for the concentration profiles around a climbing dislocation. This is done in order to determine the slowdown in dislocations velocity due to solute drag. The results show a loss in creep strength as the Laves phase grows.

Quantification of High Temperature Strength of Nickel-Based Superalloys

2007 ◽  
Vol 546-549 ◽  
pp. 1319-1326 ◽  
Author(s):  
Zhan Li Guo ◽  
N. Saunders ◽  
Alfred Peter Miodownik ◽  
J.P. Schille
Keyword(s):  
Solid Solution ◽  
High Temperature ◽  
Tensile Deformation ◽  
Model Development ◽  
High Temperature Strength ◽  
Solid Solution Strengthening ◽  
Wide Range ◽  
Solution Strengthening ◽  
Deformation Modes ◽  
Good Agreement

The strength of nickel-based superalloys usually consists of solid solution strengthening from the gamma matrix and precipitation hardening due to the gamma' and/or gamma" precipitates. In the present work, a model was developed to calculate the high temperature strength of nickel-based superalloys, where the temperature dependence of each strengthening contribution was accounted for separately. The high temperature strength of these alloys is not only a function of microstructural changes in the material, but the result of a competition between two deformation modes, i.e. the normal low to mid temperature tensile deformation and deformation via a creep mode. Extensive validation had been carried out during the model development. Good agreement between calculated and experimental results has been achieved for a wide range of nickel-based superalloys, including solid solution alloys and precipitation-hardened alloys with different type/amount of precipitates. This model has been applied to two newly developed superalloys and is proved to be able to make predictions to within useful accuracy.

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