| Title |
Solidification Microstructure Map with Solidification Processing Parameters in a CMSX-10 Single Crystal Superalloy |
| Authors |
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) |
| DOI |
https://doi.org/10.3365/KJMM.2013.51.3.199 |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
alloys; solidification; microstructure; undercooling |
| 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. |