Grain boundary serration tuning and its effect on hot workability of a wrought superalloy
CHEN, Tso-Wei
PhD. Program in Prospective Functional Materials Industry,
High Entropy Materials Center
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PhD. Program in Prospective Functional Materials Industry,
High Entropy Materials Center
CHEN, Tso-Wei
PhD. Program in Prospective Functional Materials Industry,
High Entropy Materials Center
PhD. Program in Prospective Functional Materials Industry,
High Entropy Materials Center
YEH, An-Chou
Department of Materials Science and Engineering
High Entropy Materials Center
PhD. Program in Prospective Functional Materials Industry,
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Department of Materials Science and Engineering
High Entropy Materials Center
PhD. Program in Prospective Functional Materials Industry,
Language
en
Article de revue
This item was published in
Journal of Alloys and Compounds. 2023, vol. 960, p. 170620
Elsevier
English Abstract
This study aims to elucidate the underlying mechanism of grain boundary serration and investigate its effects on hot workability of U720Li superalloy. Industrial scale as-cast ingots were subjected to heat treatments at ...Read more >
This study aims to elucidate the underlying mechanism of grain boundary serration and investigate its effects on hot workability of U720Li superalloy. Industrial scale as-cast ingots were subjected to heat treatments at 1180 °C followed by different cooling rates (15 °C/s, 0.1 °C/s, 0.02 °C/s and 0.003 °C/s) prior hot deformation. With 15 °C/s fast cooling, samples possessed straight boundaries and fine L12 structured γ’ particles dispersion. When the cooling rate was decreased to 0.1 °C/s and below, continuous and discontinuous precipitation of the γ' phase led to the formations of Type-I and Type-II grain boundary serrations, respectively. Lamellar γ/γ’ behind the mobile grain boundary was observed for Type-II boundary, which exhibited larger degree of undulation than that of Type-I boundary. With increasing fractions of Type-II boundary, the hot formability of U720Li was significantly improved during compression tests at 1000 °C; 70 % reduction ratio (true strain=1.2) could be achieved without crack formation. This work presents a simple process route to improve the hot deformability of U720Li fabricated on an industrial scale.Read less <
Origin
Hal imported