Mechanical Strength Modeling of Particle Strengthened Nickel-Aluminum Alloys Strengthened by Intermetallic γ′ (Ni3Al) Precipitates

Peak Aged Condition ◽

Peak Aged ◽

Solution Strengthening ◽

Particle Strengthening ◽

Strength Modeling ◽

Abstract A Nickel-Aluminum alloy strengthened by γ′ (Ni3Al) intermetallic ordered coherent precipitates with a small misfit strain was used a demonstration material to develop a model to predict strengthening behavior during plastic deformation as a consequence of the γ′ particles acting as obstacles to the dislocations and thus impeding their glide motion through the alloy. It was determined that the two most dominate strengthening mechanisms in the Ni-Al system were order hardening when the particles were smaller than the critical looping radius, and Orowan strengthening when the particles were larger than the looping radius. In the overaged condition when the particles are large in size, the dislocations bypass and loop the particles by the Orowan mechanism. In the underaged to peak aged conditions where the particles are usually smaller than the looping radius, the dislocations shear the precipitates during deformation. The total polycrystalline yield strength included contributions from the intrinsic lattice strength, the solid solution strengthening, grain size strengthening, and particle strengthening which included the order hardening and Orowan strengthening contributions. The total mechanical yield strength for a Ni-6.27wt.%A1 alloy was predicted for the peak-aged condition based on the theory for order strengthening and was found to be in good agreement with the experimental peak-strength data for Ni-6.27A1.

Atomistic Studies of Deformation Mechanism of Nanocrystalline Al-Ti and Al-Fe Alloys from First-Principles

10.4028/www.scientific.net/msf.561-565.977 ◽

2007 ◽

Vol 561-565 ◽

pp. 977-980 ◽

Cited By ~ 4

Author(s):

Tokuteru Uesugi ◽

Yorinobu Takigawa ◽

Kenji Higashi

Keyword(s):

Solid Solution ◽

Yield Strength ◽

First Principles ◽

Misfit Strain ◽

First Principles Calculation ◽

High Yield ◽

Solution Strengthening ◽

Analytical Result ◽

We investigated the contribution to the high yield strength due to the solid solution strengthening in nanocrystalline Al-Ti alloys produced by a vapor quench method. The misfit strain due to solute Ti atom in aluminum was obtained from the first principles calculation. Then, the theoretical result of the contribution to the yield strength due to the solid solution strengthening was estimated from the misfit strain using the Friedel’s theory. In dilute Al-Ti alloy, the theoretical results of the solid solution strengthening from the misfit strain was in good agreement with the analytical result using the measured grain size and yield stress.

Deformation Mechanism of Nanocrystalline Al-Fe Alloys by Analysis from Ab-Initio Calculations

10.4028/www.scientific.net/msf.503-504.209 ◽

2006 ◽

Vol 503-504 ◽

pp. 209-214 ◽

Cited By ~ 7

Author(s):

Tokuteru Uesugi ◽

Yorinobu Takigawa ◽

Kenji Higashi

Keyword(s):

Experimental Data ◽

Solid Solution ◽

Yield Strength ◽

First Principles ◽

High Strength ◽

Misfit Strain ◽

Solution Strengthening ◽

Fe Alloys ◽

Quench Method

Recently nanocrystalline Al-Fe alloys produced by a vapor quench method have been reported. These alloys are supersaturated solid solution and exhibit high strength with good ductility. It is postulated that the high strength of the Al-Fe alloys could be achieved by both the nano-grained structures and the solid solution strengthening. The contribution to the yield strength due to both the grain size strengthening and the solid solution strengthening were analyzed from the experimental data. Then the contribution to the yield strength due to the solid solution strengthening was estimated from the misfit strain calculated from the first principles in order to compare with analytical results estimated from the experimental data.

Multi-strengthening-mechanisms in a novel titanium alloy with (TiHf)5Si3 particle-reinforcement

MATEC Web of Conferences ◽

10.1051/matecconf/202032111078 ◽

2020 ◽

Vol 321 ◽

pp. 11078

Author(s):

Yan Du ◽

Jinwen Lu ◽

Wei Zhang ◽

Yusheng Zhang

Keyword(s):

Dislocation Motion ◽

Heat Treatments ◽

Triple Junctions ◽

Strengthening Mechanisms ◽

Particle Reinforcement ◽

Long Period ◽

Solution Strengthening ◽

Dislocation Strengthening ◽

Particle Strengthening

The microstructure and mechanical properties of Ti-2Si-2Nb-2Fe-1Hf-1Ta-1W alloy with (TiHf)5Si3 particle-reinforcement and their underlying relations have been studied. Electron microscope observations and correlative statistical analysis have been made to analyze microstructure evolution with heat treatments. The (TiHf)5Si3 particles with 800 nm in diameter were found uniformly distributed at α/β boundaries and triple junctions and turned out to be stable even after heat treatments at high temperature for a long period, inhibiting grain growth and dislocation motion. In addition, multi-strengthening-mechanisms including particle strengthening, solid-solution strengthening, grain boundary strengthening and dislocation strengthening have been discussed.

Modeling Precipitation Hardening and Yield Strength in Cast Al-Si-Mg-Mn Alloys

Metals ◽

10.3390/met10101356 ◽

2020 ◽

Vol 10 (10) ◽

pp. 1356 ◽

Cited By ~ 1

Author(s):

Emre Cinkilic ◽

Xinyan Yan ◽

Alan A. Luo

Keyword(s):

Heat Treatment ◽

Yield Strength ◽

Precipitate Morphology ◽

Casting Alloys ◽

Precipitate Shape ◽

Optimized Model ◽

Solution Strengthening ◽

Die Castings ◽

Pressure Die Casting

An integrated precipitation and strengthening model, incorporating the effect of precipitate morphology on precipitation kinetics and yield strength, is developed based on a modified Kampmann–Wagner numerical (KWN) framework with a precipitate shape factor. The optimized model was used to predict the yield strength of Al-Si-Mg-Mn casting alloys produced by vacuum high pressure die casting at various aged (T6) conditions. The solid solution strengthening contribution of Mn, which is a common alloying element to avoid die soldering, was included in the model to increase the prediction accuracy. The experimental results and simulations show good agreement and the model is capable of reliably predicting yield strength of aluminum die castings after T6 heat treatment, providing a useful tool to tailor heat treatment for a variety of applications.

Effect of APB Microsegregation on the Strength of Ni3Al with Ternary Additions

MRS Proceedings ◽

10.1557/proc-213-87 ◽

1990 ◽

Vol 213 ◽

Author(s):

Y.P. WU ◽

J.M. Sanchez ◽

J.K. Tien

Keyword(s):

Solid Solution ◽

Theoretical Model ◽

Yield Strength ◽

Local Concentration ◽

Antiphase Boundaries ◽

Alloying Additions ◽

Solution Strengthening ◽

Ternary Additions ◽

Ternary Intermetallic Compounds

ABSTRACTSolid solution strengthening for stoichiometric and non-stoichiometric alloys is studied using a microscopic model that takes into account the micro-segregation of the alloying additions and of the host atoms to antiphase boundaries. Experimental results for four ternary intermetallic compounds, Ni-Al-Si, Ni-Al-Ti, Ni-Al-Hf and Ni-Al-V, are analyzed in the light of the theoretical model. It is found that the athermal increment of yield strength for both stoichiometric and non-stoichiometric alloys can be explained using solid solution strengthening theory provided that the local concentration at the {111} antiphase boundaries between superpartial dislocations is used.

Quantification of High Temperature Strength of Nickel-Based Superalloys

10.4028/www.scientific.net/msf.546-549.1319 ◽

2007 ◽

Vol 546-549 ◽

pp. 1319-1326 ◽

Cited By ~ 13

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 ◽

Wide Range ◽

Solution Strengthening ◽

Deformation Modes ◽

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.

The Effect of Test Temperature on Deformation Microstructure and Fracture Mechanisms in CrMn High-Nitrogen Steels Alloyed (0-3 wt.%) with Vanadium

10.4028/www.scientific.net/msf.941.27 ◽

2018 ◽

Vol 941 ◽

pp. 27-32 ◽

Cited By ~ 4

Author(s):

Elena Astafurova ◽

Valentina Moskvina ◽

Galina G. Maier ◽

Eugene Melnikov ◽

Nina Galchenko ◽

...

Keyword(s):

Solid Solution ◽

Test Temperature ◽

Room Temperature ◽

High Nitrogen ◽

Interstitial Solid Solution ◽

Vanadium Concentration ◽

Solution Strengthening ◽

Nitrogen Steels ◽

Particle Strengthening

A temperature dependence of the tensile mechanical properties, microstructure and fracture mechanism of high-nitrogen Fe-(19-23)Cr-(17-21)Mn-(0-3)V-(0.1-0.3)C-(0.5-0.9)N vanadium-free and vanadium-containing steels was investigated. For all steels, the 0.2% offset yield strength and strain-hardening drastically increase with a decrease in test temperature. This is associated with high interstitial solid solution strengthening of the steels and more pronounced twinning and stacking-fault formation during straining below room temperature. For the vanadium-free steel, a ductile-to-brittle transition was evaluated: at 77K specimens destroy by cleavage mechanism while at room temperature steels show ductile fracture. Vanadium-alloying provides a particle strengthening of the steels and, at the same time, reduce solid-solution strengthening. Increase of vanadium concentration fully or partially suppress brittle fracture of the steels at 77K. Particle strengthening changes interstitial solid-solution effect, dislocation arrangement and slip/twinning relation in vanadium-containing high-nitrogen steels compared to vanadium-free one.

Mechanical Behavior of Fresh and Tempered Martensite in a CrMoV-Alloyed Steel Explained by Microstructural Evolution and Strength Modeling

Metallurgical and Materials Transactions A ◽

10.1007/s11661-020-05922-x ◽

2020 ◽

Vol 51 (10) ◽

pp. 5077-5087

Author(s):

Tao Zhou ◽

Jun Lu ◽

Peter Hedström

Keyword(s):

Yield Strength ◽

Mechanical Behavior ◽

Total Elongation ◽

Test Results ◽

Effective Grain Size ◽

Fresh Martensite ◽

The Individual ◽

Strength Modeling ◽

Strength And Ductility ◽

Abstract The mechanical behavior of a wear-resistant CrMoV-alloyed martensitic steel in quenched and tempered conditions has been investigated and correlated with the microstructure. The steel has a combination of ultra-high tensile strength of 2065 MPa and total elongation of 7.4 pct in the as-quenched condition. The strength and ductility of the steel change initially during tempering and thereafter remain quite stable during tempering at either 450 °C or 550 °C. A good combination of yield strength and total elongation is achieved after tempering at 550 °C for 2 to 8 hours (about 1300 MPa and 14 pct). The evolution of the mechanical properties can be mainly related to an initial condition with high density of dislocations (in the order of 1015) and carbon in solid solution, while quite early during tempering, dislocations will start to annihilate and carbide precipitates form. On the other hand, there is a negligible evolution of the effective grain size during tempering. Modeling of the individual strengthening mechanisms and the overall yield strength is in good agreement with the tensile test results, in particular for the tempered samples. Finally, the relatively low yield strength of the fresh martensite, significantly lower than for the tempered conditions, is discussed in relation to the two available theories.