Dissolution mechanisms and kinetics of δ phase in an aged Ni-based superalloy in hot deformation process

He, Dao‐Guang; Lin, Y.C.; Jiang, Xing-You; Yin, Liang‐Xing; Wang, Lihua; Wu, Qiao

doi:10.1016/j.matdes.2018.06.058

Cited by 71 publications

(14 citation statements)

References 71 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Dislocations indeed accelerate diffusion. More specifically for Inconel 718 it has been reported in the literature that dislocations can boost diffusion of Nb atoms [58,59] which are involved in the formation of δ phase. As a consequence, the δ phase content obtained after deformation at = 0.001 is higher than the one resulting from a static heat treatment at 980°C for the same duration on initial state material (see Figure 11).…”

Section: δ Phase Particlesmentioning

confidence: 99%

Influence of strain rate on subsolvus dynamic and post-dynamic recrystallization kinetics of Inconel 718

et al. 2019

View full text Add to dashboard Cite

Influence of strain rate on dynamic and post-dynamic recrystallization kinetics of Inconel 718 is investigated by performing hot compression tests at constant strain rate in the range 0.001; 1 in the -subsolvus domain, with or without post-deformation holding at the deformation temperature. Dynamically and post-dynamically recrystallized grains are distinguished based on their internal misorientations, using EBSD data with enhanced angular resolution. For the applied deformation conditions ( = 980° and = 0.7), dynamic recrystallization is inhibited at > 0.1 . On the other hand, very fast post-dynamic recrystallization is promoted by high strain rates, with characteristic times which can be as short as few seconds to achieve full recrystallization. Most of previous works on the effect of strain rate on dynamic recrystallization kinetics were done by quenching samples right after deformation, without discriminating dynamically and post-dynamically recrystallized grains. Those works led to the conclusion that increasing strain rate beyond a critical value leads to an increase in dynamic recrystallization kinetics. Experimental quenching delays cannot be shorter that few seconds, which is shown here to be sufficient to get a significant increase in recrystallized fraction by post-dynamic mechanisms. Based on the present work, postdynamic evolutions are actually very likely to be responsible for the apparent increase in dynamic recrystallization kinetics at high strain rates which has often been reported previously.

show abstract

Section: δ Phase Particlesmentioning

confidence: 99%

Influence of strain rate on subsolvus dynamic and post-dynamic recrystallization kinetics of Inconel 718

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Once the accumulated dislocation density exceeds the critical strain for DRX, the nucleation and growth of DRX grains proceed, which cause the annihilation and rearrangement of dislocation, and the work hardening is weaken. Especially, DRX plays the dominant role on dynamic softening after the peak stress [21,24,32]. Therefore, the true stress is continuously decreased.…”

Section: Resultsmentioning

confidence: 99%

“…Inconel 718 superalloy, as a typical nickel-base superalloy, is extensively applied in aerospace and energy industries, due to its superior mechanical properties. Moreover, its good workability makes forging and welding easy [22][23][24][25][26][27]. For Inconel 718 superalloy, Arrhenius-type constitutive equations were also used to describe hot deformation behaviors [16,28].…”

Section: Introductionmentioning

confidence: 99%

A Strain-Compensated Constitutive Model for Describing the Hot Compressive Deformation Behaviors of an Aged Inconel 718 Superalloy

Zhou

Chen

Qin

2018

High Temperature Materials and Processes

View full text Add to dashboard Cite

The hot deformation behaviors of an aged Inconel 718 superalloy are investigated by isothermal compression experiments at four strain rates and five deformation temperatures on a Gleeble-3500 thermo-mechanical simulator. The experimental results show that the true stresses are obviously affected by strain rate and deformation temperature. The true stress increases rapidly at the beginning of hot compressive deformation, which ascribes to the intense work hardening. The true stresses at high deformation temperatures are lower than those at lower deformation temperatures. The dynamic softening induced by DRX is weak at a relatively low deformation temperature. A strain-compensated Arrhenius-type constitutive equation linked with true stress, strain rate and deformation temperature is developed for the studied superalloy. The material constants (\alpha , n, Q and A) in the developed model are expressed as the functions of true strain. The flow stresses calculated by the developed constitutive equation are nicely consistent with the experimental ones, which confirms that the developed constitutive equation can accurately describe the hot deformation behaviors of the studied superalloy.

show abstract

“…The Cauchy pressure, illustrated as (C 12 -C 44 ) [39], should be an effective indicator to evaluate the ductile/brittle nature of cubic crystals. In Pettifor's work [40], a more positive Cauchy pressure symbolized better ductility in the compound [41].…”

Section: Elastic Constantsmentioning

confidence: 99%

Insight into Physical and Thermodynamic Properties of X3Ir (X = Ti, V, Cr, Nb and Mo) Compounds Influenced by Refractory Elements: A First-Principles Calculation

Chen

Geng

et al. 2019

Crystals

View full text Add to dashboard Cite

The effects of refractory metals on physical and thermodynamic properties of X3Ir (X = Ti, V, Cr, Nb and Mo) compounds were investigated using local density approximation (LDA) and generalized gradient approximation (GGA) methods within the first-principles calculations based on density functional theory. The optimized lattice parameters were both in good compliance with the experimental parameters. The GGA method could achieve an improved structural optimization compared to the LDA method, and thus was utilized to predict the elastic, thermodynamic and electronic properties of X3Ir (X = Ti, V, Cr, Nb and Mo) compounds. The calculated mechanical properties (i.e., elastic constants, elastic moduli and elastic anisotropic behaviors) were rationalized and discussed in these intermetallics. For instance, the derived bulk moduli exhibited the sequence of Ti3Ir < Nb3Ir < V3Ir < Cr3Ir < Mo3Ir. This behavior was discussed in terms of the volume of unit cell and electron density. Furthermore, Debye temperatures were derived and were found to show good consistency with the experimental values, indicating the precision of our calculations. Finally, the electronic structures were analyzed to explain the ductile essences in the iridium compounds.

show abstract

Dissolution mechanisms and kinetics of δ phase in an aged Ni-based superalloy in hot deformation process

Cited by 71 publications

References 71 publications

Influence of strain rate on subsolvus dynamic and post-dynamic recrystallization kinetics of Inconel 718

Influence of strain rate on subsolvus dynamic and post-dynamic recrystallization kinetics of Inconel 718

A Strain-Compensated Constitutive Model for Describing the Hot Compressive Deformation Behaviors of an Aged Inconel 718 Superalloy

Insight into Physical and Thermodynamic Properties of X3Ir (X = Ti, V, Cr, Nb and Mo) Compounds Influenced by Refractory Elements: A First-Principles Calculation

Contact Info

Product

Resources

About