The influence of crystallography and creep ductility on thermal fatigue crack initiation in nickel-base superalloys with elongated macrograins

Blümm, M.; deMestral, Bernard; Eggeler, Gunther; Rézaï-Aria, Farhad

doi:10.1016/0956-716x(95)00229-o

Cited by 6 publications

(6 citation statements)

References 3 publications

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“…It was different from other experimental results [7,8]. Literatures [7,8] showed that propagation rate of crack started to increase and then decrease when the crack length was 5 -6 mm. The reason is that it creates large stress near crack in the course of thermal fatigue experiment.…”

Section: Resultscontrasting

confidence: 68%

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Influence of direction of notch on thermal fatigue property of a directionally solidified nickel base superalloy

Xia

Yang

et al. 2011

Rare Metals

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Thermal fatigue property of a directionally solidified nickel base superalloy at the condition of different notched orientation and upper temperatures was investigated. The results show that cycle numbers of crack initiation decrease, propagation rate of crack increases and resistance of thermal fatigue reduces with the rise of upper temperature. Thermal fatigue property of the specimen with the notched direction vertical to orientation of dendrite growth (DZ319T) is superior to that of the specimen with the notched direction parallel to orientation of dendrite growth (DZ319L). DZ319L alloy initiates thermal fatigue crack by carbide and propagates along the direction of carbide distribution, which resultes in big propagation rate and poor thermal fatigue property. Crack initiation of DZ319T alloy is mainly by oxidized cavity. The join of oxidized cavity makes crack propagate. There are two cracks in DZ319T alloy, which greatly drops the stress concentration near the notch and decreases the propagation rate of crack. DZ319T alloy has excellent thermal fatigue property.

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Section: Resultscontrasting

confidence: 68%

“…It is difficult to compare thermal fatigue results by different investigation. Some experiment results [3][4][5][6][7][8][9][10][11][12][13][14][15] show thermal fatigue property of the alloy is greatly affected by different factors such as upper temperature, holding time, specimen shape, notched radius and direction.…”

Section: Introductionmentioning

confidence: 99%

Influence of direction of notch on thermal fatigue property of a directionally solidified nickel base superalloy

Xia

Yang

et al. 2011

Rare Metals

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“…15 Several alloys with elongated grains have been investigated including cast and powder metallurgy (mechanically alloyed materials) produced materials. [16][17][18][19][20] Both creep fatigue and TMF experiments have been conducted on as cast or cast and heat treated conditions. TMF experiments were performed on CM 247LC, a directionally solidified alloy, using single wedge specimens and a temperature-time cycle with a minimum temperature of 200uC and a maximum temperature of 1000uC; 16 CM 247LC is a derivative of MAR-M247.…”

Section: Single Crystal and Directionally Oriented Microstructuresmentioning

confidence: 99%

“…[16][17][18][19][20] Both creep fatigue and TMF experiments have been conducted on as cast or cast and heat treated conditions. TMF experiments were performed on CM 247LC, a directionally solidified alloy, using single wedge specimens and a temperature-time cycle with a minimum temperature of 200uC and a maximum temperature of 1000uC; 16 CM 247LC is a derivative of MAR-M247. The maximum tensile stress in the specimens was perpendicular to the elongated macrograins.…”

Section: Single Crystal and Directionally Oriented Microstructuresmentioning

confidence: 99%

“…The surrounding microstructure may also influence crack nucleation in ODS superalloys. MA760 was tested under TMF conditions using a single wedge specimen with the same loading conditions cited previously for CM 247LC, 16 and was also tested so the applied stress was transverse to the elongated grains. Thermal fatigue cracks nucleated in grain boundaries beside grains with high moduli and low Schmid factors perpendicular to the thermal fatigue crack, largely because thermal stresses cannot relax due to unfavourable orientations for slip in the adjacent grains.…”

Section: Crack Nucleation In Superalloysmentioning

confidence: 99%

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A critical assessment of fatigue crack nucleation and growth models for Ni- and Ni,Fe-based superalloys

Findley

Evans

Saxena

2011

International Materials Reviews

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Ni-and Ni,Fe-based superalloys are used extensively in the hot sections of gas turbines in the aerospace and power generation industries. One way to improve the performance of turbines is through increased operating temperatures and stresses. Therefore, an understanding of the factors that influence resistance of these materials to creep and fatigue is necessary to build models that can predict the lives of components in these harsh operating conditions. Predicting crack nucleation (or formation) and the subsequent rate of crack propagation is a complex problem because of the interactions between microstructure, cyclic deformation, and the high temperature effects of creep and environment; an additional influence is variable amplitude loading during the service life. This paper will discuss the pertinent research over the past three decades that has considered microstructural, temperature, environmental, frequency and loading effects on fatigue crack growth in these important intermediate temperature alloys and is divided into sections devoted to crack nucleation, short crack growth, and long crack growth.

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Analysis of damage during bending creep tests

Xu¹,

Zhu²,

Chen³

2009

Philosophical Magazine Letters

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The influence of crystallography and creep ductility on thermal fatigue crack initiation in nickel-base superalloys with elongated macrograins

Cited by 6 publications

References 3 publications

Influence of direction of notch on thermal fatigue property of a directionally solidified nickel base superalloy

Influence of direction of notch on thermal fatigue property of a directionally solidified nickel base superalloy

A critical assessment of fatigue crack nucleation and growth models for Ni- and Ni,Fe-based superalloys

Analysis of damage during bending creep tests

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