Fatigue crack path prediction in UDIMET 720 nickel-based alloy single crystals

Reed, P.A.S.; Wu, X.D.; Sinclair, Ian

doi:10.1007/s11661-000-0058-6

Cited by 86 publications

(63 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…6. The proposed crack-propagation criterion (11) under the thermal cyclic loadings demonstrates a satisfactory accuracy in comparison with the experimentally obtained number of cycles to failure and the crackfront evolution indicated by the data of a fractography analysis. 7.…”

Section: Criterion For the Tmf-crack Propagationmentioning

confidence: 64%

“…The direction of a crack propagation in a single crystal is defined by the crystallographic structure (typically it is plane 〈 〉 111 for the considered alloys 11,12 in the crystallographic mode of failure) and, correspondingly, it is defined by the stress state during the non-crystallographic failure mode (a high temperature).…”

Section: Criterion For the Tmf-crack Propagationmentioning

confidence: 99%

“…It demonstrates a good correlation with the data of a fractography analysis (Figure 11b). Number of cycles FE computation with (11) 192 Experiment 125 corset specimens under the thermal cyclic loading were performed using different material models. The obtained results indicate an applicability of the proposed deformation criteria for failure for the five considered single-crystal alloys at temperatures of up to 1100°C.…”

Section: Criterion For the Tmf-crack Propagationmentioning

confidence: 99%

See 2 more Smart Citations

Thermal fatigue of single-crystal superalloys: experiments, crack-initiation and crack-propagation criteria

Getsov¹,

Семенов²,

...³

2015

Mater. Tehnol.

View full text Add to dashboard Cite

Thermal-fatigue tests were performed on corset samples made from five single-crystal nickel-based superalloys with various crystallographic orientations (〈 〉 001 ,〈 〉 011 ,〈 〉 111 ) at different temperatures and cycle durations. The proposed criteria for the thermal-fatigue crack initiation and crack propagation are discussed and compared with experimental results. The sensitivity of durability to the crystallographic orientation and to thermal-cycle parameters is analyzed experimentally and by means of the corresponding finite-element simulations. Keywords: nickel-based superalloy, single crystal, thermal fatigue, crack initiation, crack propagation Preizkusi toplotnega utrujanja so bili izvr{eni na vzorcih korzetne oblike. Vzorci so bili izdelani iz petih monokristalnih nikljevih superzlitin z razli~no kristalografsko orientacijo (〈 〉 001 ,〈 〉 011 ,〈 〉 111 ), preizkusi pa so bili narejeni pri razli~nih temperaturah trajanja ciklov. Predlagana merila za nastanek razpok in njihovo napredovanje pri toplotnem utrujanju so opisana in primerjana z eksperimentalnimi rezultati. Odvisnost zdr`ljivosti od kristalografske orientacije in parametrov toplotnih ciklov je eksperimentalno analizirana in ugotovljena z ustrezno simulacijo s kon~nimi elementi. Klju~ne besede: superzlitina na osnovi niklja, monokristal, toplotno utrujanje, nastanek razpok, napredovanje razpoke EXPERIMENTAL DATAThe durability of the single-crystal blades of modern gas turbines is mainly determined by their ability to resist the thermal-cycling stress. In Russia, the testing of the thermal fatigue of corset samples (Figure 1) in vacuum conditions, with and without lateral thermal-barrier coatings is widespread. During the test, the shearband formation, the conditions of crack nucleation and the rate of crack propagation are investigated.Experimental studies were performed on five singlecrystal alloys (ZhS32, ZhS36 and others) developed by the VIAM research centre, with different alloying and, most importantly, different carbon contents. The chemical compositions of the alloys are given in Table 1.The tests of the thermal-fatigue resistance were carried out for different crystallographic orientations (CGOs) of the specimens, various minimum (T min ) and maximum temperatures (T max ) of the cycle, with and without a dwell time at T max . 1,2 The test results were characterized with the number of cycles to the macrocrack initiation and to the failure of the samples and the in-plane and out-of-plane residual strains (e in , e out ) in the central parts of the specimens. The changing of T max and CGO has a significant influence on the thermal-cycling durability ( Table 2).The results of a comparative analysis of the thermalfatigue durabilities of the five considered alloys are given in Figure 2, for a thermal cycle of 150«900°C (Figures 2a and 2c) and for a cycle of 500«1050°C (Figures 2b and 2d).

show abstract

Section: Criterion For the Tmf-crack Propagationmentioning

confidence: 64%

Section: Criterion For the Tmf-crack Propagationmentioning

confidence: 99%

Section: Criterion For the Tmf-crack Propagationmentioning

confidence: 99%

See 1 more Smart Citation

Thermal fatigue of single-crystal superalloys: experiments, crack-initiation and crack-propagation criteria

Getsov¹,

Семенов²,

...³

2015

Mater. Tehnol.

View full text Add to dashboard Cite

show abstract

“…The two first cases (Fig 11 A and B) occur regularly during the growth of a crack, but do not necessarily develop into a macroscopically deflected crack. Periodic changes in crack path on a microscopic scale may actually cause slower fatigue crack growth rates [8]. Clearly further analysis of the evolving crack-tip stress state for this complex phenomenon is required.…”

Section: Discussionmentioning

confidence: 99%

Sustained Macroscopic Deflected Fatigue Crack Growth in Nickel Based Superalloy 720Li

Schoettle¹,

Reed²,

Starink³

et al. 2012

Superalloys 2012 (Twelfth International Symposium)

Self Cite

View full text Add to dashboard Cite

Sustained deflected crack growth is a concern as we need to understand both the factors which cause it and when it may happen in a component to ensure we have appropriate lifing strategies in place. This behaviour has been reported in a number of fine-grained Ni-based turbine disc alloys at intermediate temperatures (200-600 o C). Such fracture surfaces show a competition between opening and shear modes of crack growth, with macroscopic deflection being initiated from the free surface. The interaction of the crack and surrounding microstructure have been studied via serial sectioning using a focused ion beam, allowing a reconstruction based on combined 3D electron back scatter diffraction (EBSD) and energy dispersive spectroscopy (EDS) to be produced. This showed both intergranular and transgranular crack growth modes occurring in the deflected crack growth and no obvious influence of grain orientation or texture to explain the crack deflection. Visualisation and representation of such data-rich images is challenging -the additional compositional (phase identification), orientation and deformation/strain mapping features of this approach together with the spatial information in 3D may require new approaches to data presentation.

show abstract

“…1500°C class gas turbine power plants use single crystal or directionally solidified Ni-based superalloys for first stage blades. In such superalloys, crystallographic cracking may occur and propagate on {111} slip planes [6,7]. If MPE cracks propagate on {111} slip plane with inclined angle, the neighboring cracks can possibly cross each other, and the blade may partially break.…”

Section: Introductionmentioning

confidence: 99%

A Proposal on Quantitative Treatment of Multiple Cracks Nucleating in Single Crystal Superalloys

Mukai¹,

Kagawa²

2012

Superalloys 2012 (Twelfth International Symposium)

View full text Add to dashboard Cite

Multiple crack propagation tests were performed at room temperature using four point bending specimens which contained nineteen cracks and were made of Ni-based single crystal superalloy CMSX-4. Two types of specimen orientations were machined. One's longitudinal direction was [010] and machined notch direction was [100], and another's was [010] and [101]. In each specimen, cracks propagated along {111} slip planes making ridges which inclined to the thickness direction. The cracks of the former also inclined to the longitudinal direction at an angle of 45°, while those of the latter propagated along the machined notch direction. To evaluate such crack propagation behavior, mode I -III stress intensity factors were calculated under three conditions. First, cracks were treated as single edge crack without considering crack interaction. Secondly, cracks were treated as multiple parallel edge cracks with same lengths. Third, cracks were treated as multiple parallel edge cracks with alternately different lengths. Since stage-I cracking was evaluated by resolved shear stress intensity factor range on {111} plane, resolved shear stress intensity factor was calculated from mode I -III stress intensity factors obtained by the above three conditions. Then, crack propagation simulations were performed. In case of the [010][101] orientation specimen, simulated crack propagation rates and behavior calculated under the third condition agreed well with the experimental ones. On the other hand, in case of the [010][100] specimen, those calculated by the first condition agreed better with the experiments than those simulated by the other conditions.

show abstract

Fatigue crack path prediction in UDIMET 720 nickel-based alloy single crystals

Cited by 86 publications

References 17 publications

Thermal fatigue of single-crystal superalloys: experiments, crack-initiation and crack-propagation criteria

Thermal fatigue of single-crystal superalloys: experiments, crack-initiation and crack-propagation criteria

Sustained Macroscopic Deflected Fatigue Crack Growth in Nickel Based Superalloy 720Li

A Proposal on Quantitative Treatment of Multiple Cracks Nucleating in Single Crystal Superalloys

Contact Info

Product

Resources

About