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Vol.51, No.3, 199 ~ 210, 2013
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| Title |
| Solidification Microstructure Map with Solidification Processing Parameters in a CMSX-10 Single Crystal Superalloy |
| 구지호 Ji Ho Gu , 정형민 Hyung Min Jung , 이정석 Jeong Seok Lee , 윤혜영 Hye Young Yoon , 서성문 Seong Moon Seo , 조창용 Chang Yong Jo , 이재현 Je Hyun Lee |
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| Abstract |
| Directional solidification experiments were carried out on a single crystal Ni base superalloy CMSX-10 over a wide range of growth velocity and temperature gradient conditions. Under the imposed temperature gradients, the primary dendrite arm spacings decreased proportionally with the growth velocity. Microstructural characteristics at the solid/liquid interface were found to depend strongly on the growth velocities and temperature gradients. Based on the experimental observations, a growth velocity versus temperature gradient map was selected for planar to cellular and cellular to dendritic transitions during solidification. As a result, the microstructure selection map for the alloy was established by comparing it to theoretical models. Good agreement was obtained from the results for planarcellular and cellular-dendritic transitions. The columnar-equiaxed transition, however, was calculated using Hunt`s model for castings. The results are discussed in terms of the combined effects of constitutional undercooling and nucleation undercooling ahead of the growing dendrite tips. |
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| Key Words |
| alloys, solidification, microstructure, undercooling |
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