%0 Journal Article %T Effect of cooling rate on MC carbide in directionally solidified nickel-based superalloy under high thermal gradient %A Zhang Weiguo %A Liu Lin %A Fu Hengzhi %J China Foundry %D 2012 %I Foundry Journal Agency %X A series of directional solidification experiments have been performed to study the effect of cooling rate on the precipitation behavior of MC carbide in nickel-based superalloy under the temperature gradient of 500 K¡¤s-1. Results reveal that the morphology of MC carbide changes from coarse block to fine strip, then to Chinese-script, and their sizes reduce gradually with the increasing of cooling rate from 2.53 K¡¤s-1 to 36.4 K¡¤s-1. At low cooling rates, most of these carbides are found to be located at the grain boundary and interdendritic regions, while the coupled growth of some carbides and ¦Ã matrix in the center of ¦Ã grains is occurred at high cooling rate. The main elements forming MC carbide are Ta, W, and Hf. %K directional solidification %K cooling rate %K nickel-based superalloy %K MC carbide %U http://www.foundryworld.com/uploadfile/2012031350254777.pdf