| Title |
Research Paper / Solidification : The effect of solidification rate on MC carbide trapping behavior during directional solidification of the superalloy Mar - M 247 LC |
| Authors |
이재현(Je Hyun Lee); 조창용(Chang Yong Jo); 서성문(Seong Moon Seo); 김두현(Doo Hyun Kim); 최승주(Seung Joo Choe) |
| Abstract |
MC carbide trapping in Mar-M 247LC alloy was systemically investigated by directional solidification and quenching method. It was found that several kinds of differently shaped carbides formed according to the distance from the dendrite tip and solidification rates. The trapping behaviors between relatively higher solidification rate and slower solidification rate were different. The calculated maximum carbide nuclei size was close to the observed value when the sample solidification rate was slow, but it was smaller than the observed value when the sample solidification rate was high. The inter-secondary dendrite arm region was the preferred trapping site. At very slow solidification rate, the bottom of the mushy zone was also a trapping site while at high solidification rate the dendrite side wall became a trapping site. Reduction of carbide volume fraction at the slow sample solidification rate was caused by the low trapping ability of the solid-liquid interface and lack of suitable solidification site in the solid-liquid interface at, the slow solidification rate. At relatively higher solidification rate, the solid-liquid interface trapped the carbide nuclei in front of the moving interface In contrast. some difficulty to trap the carbide nuclei occurred at the slower solidification rate. |