A new approach to dislocation creep

Oruganti, Ramkumar

doi:10.1016/j.actamat.2011.11.051

Cited by 22 publications

(11 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For instance, if a material weakens with time due to coarsening of strengthening particles, the plot will reflect this by curving downward. A good example of this is the case of ferritic steels where nanoscale carbonitrides coarsen and weaken the material [6]. The data for superalloys, on the other hand, appear to curve upwards as shown in Fig.…”

Section: Introductionmentioning

confidence: 93%

A New Approach to Modeling of Creep in Superalloys

et al. 2012

View full text Add to dashboard Cite

A new theory of superalloy creep is presented. It is argued that ' particles in superalloys do not play a rate-controlling role during creep. They are hypothesized to act as composite reinforcements regardless of their size. The rate-controlling role is ascribed to dislocation related obstacles such as nodes, jogs or kinks.The basic constitutive law based on this premise is shown to be capable of representing the time to strain data of a wide range of superalloys. Equations for primary and tertiary creep are developed based on the composite concept and are shown to predict the creep behavior of DS-GTD111 TM a superalloy commonly used in gas turbines. The new approach is also shown to be capable of explaining a wide range of observations reported in the literature. The implications of these findings in terms of the effect of microstructure on creep behavior are discussed.

show abstract

Section: Introductionmentioning

confidence: 93%

A New Approach to Modeling of Creep in Superalloys

et al. 2012

View full text Add to dashboard Cite

show abstract

“…A critique on the usefulness of the different models is challenging for a number of reasons. Oruganti [33,46] pointed out that cases of poor correspondence between experiments and model predictions are often attributed to gaps in understanding damage mechanisms rather than to the basic constitutive creep laws used. As such, the critical assessment of these laws is of importance.…”

Section: Mclean Andmentioning

confidence: 99%

Critical assessment 31: On the modelling of tertiary creep in single-crystal superalloys

Sulzer

Reed

2018

Materials Science and Technology

View full text Add to dashboard Cite

Modelling of tertiary creep in single-crystal superalloys -operative over the majority of the temperature/stress regime of relevance -is assessed. Traditional, empirical approaches are useful for the prediction of component life; a modern trend is for more physically faithful models which account for microstructure and alloy composition. Calculations are made using different methods, to identify advantages/disadvantages, in an effort to approach best practice. The predictions are tested against experimental data. The creep resistance can be estimated to within approximately one-half of a Larson-Miller parameter, from an input of alloy composition, deformation conditions, and estimates of microstructural parameters, rate laws (and parameters therein), and physical constants. Different merit indices are considered to identify the most appropriate for compositional optimisation.

show abstract

“…This microstructural stability should have potential beneficial effect. However, the aforementioned exposure-or creep-induced inversion usually accompanies with multi-scale structural damages [18,19,[23][24][25][26][27][28], such as alloying elements segregation, dislocation propagation, γ /γ ' interface distortion, deleterious phase precipitation and micro-voids growth, leading to poor mechanical properties. There is still a lack of research to distinguish the effect of topological inversion from the above harmful impacts.…”

Section: Introductionmentioning

confidence: 99%

Topologically inverse microstructure in single-crystal superalloys: microstructural stability and properties at ultrahigh temperature

Zhao

et al. 2021

Materials Research Letters

View full text Add to dashboard Cite

Topological phase inversion, in which γ '-precipitate becomes topological matrix phase, is a typical 'detrimental' microstructural degradation in Ni-based single-crystal superalloys. Here, a topologically inverse structure without service-induced damages is proposed. This structure exhibits excellent stress rupture properties at 1200°C and great microstructural stability, characterized by high, steady two-phase interface density. The relationship of the interface density to microscopic dislocation motion and macroscopic plastic deformation has been established, which reveals possible strengthening effect. These results will help understanding the benefit from this 'degraded' but quite stable microstructure and guide microstructure tuning against long-termed heat-resisted service. IMPACT STATEMENTTopological phase inversion achieved after heat treatment exhibits great microstructural stability and enhanced 1200°C stress rupture properties of single-crystal superalloys. The mechanism behind this beneficial effect is uncovered.

show abstract

A new approach to dislocation creep

Cited by 22 publications

References 17 publications

A New Approach to Modeling of Creep in Superalloys

A New Approach to Modeling of Creep in Superalloys

Critical assessment 31: On the modelling of tertiary creep in single-crystal superalloys

Topologically inverse microstructure in single-crystal superalloys: microstructural stability and properties at ultrahigh temperature

Contact Info

Product

Resources

About