Crystallization and microstructure of Co0.75Ni0.25Si2 solid solution

The microstructure of Co0.75Ni0.25Si2 solid solution, obtained by two different techniques was studied. The solidification processes were conducted using Bridgman and Czochralski methods. The processes were conducted under atmospheric pressure and in the helium atmosphere. Various pulling down (Bridgman method) and pulling up (Czochralski method) rates were applied for ingots and boules preparation. The obtained Co0.75Ni0.25Si2 ingots and boules were subjected to the metallographic observations and chemical microanalysis, mainly used Scanning Electron Microscopy techniques. They were studied using X-ray phase analysis too. Comparing the investigation results it was found that the ingots obtained by the Bridgman method and boules obtained by the Czochralski method were single crystalline. The boules, obtained using the Czochralski method, possess better structural quality than ingots obtained by the Bridgman method.