A single crystal Ni-base superalloy was processed with withdrawal rates between 2 and 7 mm/min. The ascast microstructures, heat treatment response and creep property have been characterized as a function of the withdrawal rate. As expected, the primary and secondary dendrite arm spacing decreased with increasing withdrawal rate; microsegregation degree and porosity distribution were also varied with different withdrawal rates. The withdrawal rate of 2 mm/min resulted in a noticeable residual microsegregation even after full heat treatment. The samples solidified at 7 mm/min exhibited a high density of cast porosities, and this led to a dramatical decline of the creep strain. 4 or 6 mm/min appeared to be the optimum withdrawal rate in the present study, which resulted in a uniform microstructure and an optimum density of cast porosity.
参考文献
| [1] | B.C. Wilson;E.R. Cutler;G.E. Fuchs .Effect of solidification parameters on the microstructures and properties of CMSX-10[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2008(1/2):356-364. |
| [2] | L. Liu;T.W. Huang;J. Zhang .Microstructure and stress rapture properties of single crystal superalloy CMSX-2 under high thermal gradient directional solidification[J].Materials Letters,2007(26):227-230. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%