Investigation of solidification behavior and associate microstructures of Co-Cr-W and Co-Cr-Mo alloy systems using DSC technique

This article presents a study of solidification behavior and the corresponding microstructure of Co-Cr-W and Co-Cr-Mo alloy systems using the differential scanning calorimetry technique. The influence of main constituents on the solidification behavior and associate microstructures of these alloys are investigated. It is found that chemical composition influences significantly the solidification behavior of cobalt-based alloys. Solution-strengthened alloy has the highest solidification temperature and narrowest solidification range. Presence of carbon decreases the solidification temperature and increases the solidification range. Addition of boron greatly decreases the solidification temperature. Carbon content dominates the solidification behavior of cobalt-based alloys when the contents of the solution-strengthening elements Mo and Ni are within their saturation in the solution matrix. However, as these contents reach a certain level, formation of intermetallic compounds changes the solidification behavior of these alloys remarkably. Increase in the contents of solution-strengthening elements reduces the solid solution transformation temperature and the eutectic temperature when carbon content is constant.