Fatigue Crack Initiation in Nickel-Based Superalloy MAR-M247 at High Temperature

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68081723%3A_____%2F17%3A00478819" target="_blank" >RIV/68081723:_____/17:00478819 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.4028/www.scientific.net/KEM.754.27" target="_blank" >http://dx.doi.org/10.4028/www.scientific.net/KEM.754.27</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.4028/www.scientific.net/KEM.754.27" target="_blank" >10.4028/www.scientific.net/KEM.754.27</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Fatigue Crack Initiation in Nickel-Based Superalloy MAR-M247 at High Temperature

Popis výsledku v původním jazyce

The present work is focused on the study of crack initiation during low cycle fatigue (LCF) loading of the second generation nickel-based superalloy MAR-M247 treated with hot isostatic pressing. LCF tests were conducted on cylindrical specimens in symmetrical push-pull cycle under strain control with constant total strain amplitude and strain rate at 800 °C in air atmosphere. Selected specimens were electrolytically polished to facilitate surface relief observations. Crack initiation sites were studied by means of scanning electron microscopy (SEM) in dual beam microscope TESCAN LYRA 3 XMU FESEM equipped with focus ion beam (FIB). The microstructure of the material is characterised by coarse dendritic grains with numerous carbides and small casting defects. The average grain size was 2.1 ± 0.3 mm. Fractographic analysis revealed the fatigue crack initiation sites and their relation to the casting defects and material microstructure. Casting defects, carbide inclusions and interdendritic areas were found to be important crack nucleation sites. Specimens’ surface observations revealed the formation of pronounced surface relief with short worm-like markings. Fatigue crack initiation in these places is documented and discussed.

Název v anglickém jazyce

Fatigue Crack Initiation in Nickel-Based Superalloy MAR-M247 at High Temperature

Popis výsledku anglicky

The present work is focused on the study of crack initiation during low cycle fatigue (LCF) loading of the second generation nickel-based superalloy MAR-M247 treated with hot isostatic pressing. LCF tests were conducted on cylindrical specimens in symmetrical push-pull cycle under strain control with constant total strain amplitude and strain rate at 800 °C in air atmosphere. Selected specimens were electrolytically polished to facilitate surface relief observations. Crack initiation sites were studied by means of scanning electron microscopy (SEM) in dual beam microscope TESCAN LYRA 3 XMU FESEM equipped with focus ion beam (FIB). The microstructure of the material is characterised by coarse dendritic grains with numerous carbides and small casting defects. The average grain size was 2.1 ± 0.3 mm. Fractographic analysis revealed the fatigue crack initiation sites and their relation to the casting defects and material microstructure. Casting defects, carbide inclusions and interdendritic areas were found to be important crack nucleation sites. Specimens’ surface observations revealed the formation of pronounced surface relief with short worm-like markings. Fatigue crack initiation in these places is documented and discussed.

Druh

D - Stať ve sborníku

CEP obor

—

OECD FORD obor

20306 - Audio engineering, reliability analysis

Projekt

<a href="/cs/project/GA15-20991S" target="_blank" >GA15-20991S: Plazmová depozice, strukturní a termomechanická stabilita environmentálních bariér</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název statě ve sborníku

Advances in Fracture and Damage Mechanics XVI

ISBN

978-3-0357-1168-4

ISSN

1662-9795

e-ISSN

—

Počet stran výsledku

4

Strana od-do

27-30

Název nakladatele

Trans Tech Publications Ltd

Místo vydání

Zurich

Místo konání akce

Florence

Datum konání akce

18. 7. 2017

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

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