Effect of carbon addition on carbide morphology of single crystal Ni-based superalloy

Single crystal superalloys of AM3 with different carbon levels were prepared at withdraw rate of 50 μm/s. The effect of carbon addition on the carbide morphology was investigated. It was found that there were four types of MC-type carbides, acicular, nodular, blocky, and Chinese script-type in the crystals. With an increase in carbon level, the volume fraction of carbide increased significantly while the volume fraction of eutectic decreased significantly. Furthermore, the size of carbide in high level carbon alloy became much larger.