Effect of composition on the matrix transformation of the Co-Re-Cr-Ta-C alloys

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389005%3A_____%2F16%3A00461724" target="_blank" >RIV/61389005:_____/16:00461724 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1007/s12540-016-5697-2" target="_blank" >http://dx.doi.org/10.1007/s12540-016-5697-2</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s12540-016-5697-2" target="_blank" >10.1007/s12540-016-5697-2</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Effect of composition on the matrix transformation of the Co-Re-Cr-Ta-C alloys

Popis výsledku v původním jazyce

Neutron diffraction measurement was performed in-situ at high temperatures on Co-Re-Ta-C alloys with and without Cr addition. This included alloys containing different C content with the C/Ta ratio varying between 0.5 and 1.0. The Co-Re-solid solution matrix of the experimental alloys is polymorphic (like in pure cobalt) and transformed from low temperature hexagonal E > phase to high temperature cubic gamma phase on heating. This transformation is reversible and show hysteresis. The main alloying addition, Re, stabilizes the E > Co-phase and increases the transformation temperature to above 1273 K. The onset of the transformation during heating and cooling was found to differ depending on the alloy composition. In alloys without Cr addition the transformation was not completed on cooling and the high temperature gamma phase was partly retained at room temperature in metastable state with the amount depending on the cooling rate from high temperature. The diffraction and microstructural results showed that Cr is E > stabilizer (similar as Re) but the role of Ta is not clear. The C/Ta ratio has no direct effect on the matrix phase transformation. Nevertheless, it influences indirectly by determining the amount of Ta which is freely available in the matrix.

Název v anglickém jazyce

Effect of composition on the matrix transformation of the Co-Re-Cr-Ta-C alloys

Popis výsledku anglicky

Neutron diffraction measurement was performed in-situ at high temperatures on Co-Re-Ta-C alloys with and without Cr addition. This included alloys containing different C content with the C/Ta ratio varying between 0.5 and 1.0. The Co-Re-solid solution matrix of the experimental alloys is polymorphic (like in pure cobalt) and transformed from low temperature hexagonal E > phase to high temperature cubic gamma phase on heating. This transformation is reversible and show hysteresis. The main alloying addition, Re, stabilizes the E > Co-phase and increases the transformation temperature to above 1273 K. The onset of the transformation during heating and cooling was found to differ depending on the alloy composition. In alloys without Cr addition the transformation was not completed on cooling and the high temperature gamma phase was partly retained at room temperature in metastable state with the amount depending on the cooling rate from high temperature. The diffraction and microstructural results showed that Cr is E > stabilizer (similar as Re) but the role of Ta is not clear. The C/Ta ratio has no direct effect on the matrix phase transformation. Nevertheless, it influences indirectly by determining the amount of Ta which is freely available in the matrix.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

BM - Fyzika pevných látek a magnetismus

OECD FORD obor

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Projekt

<a href="/cs/project/GB14-36566G" target="_blank" >GB14-36566G: Multidisciplinární výzkumné centrum moderních materiálů</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2016

Kód důvěrnosti údajů

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

Název periodika

Metals and Materials International

ISSN

1598-9623

e-ISSN

—

Svazek periodika

22

Číslo periodika v rámci svazku

4

Stát vydavatele periodika

KR - Korejská republika

Počet stran výsledku

10

Strana od-do

562-571

Kód UT WoS článku

000379535700003

EID výsledku v databázi Scopus

2-s2.0-84978080362