Microstructural development in rapidly solidified silicon-rich alloys

Morphological properties and solidification characteristics of some Si-rich alloys containing various amounts of Al, Cu, V, Co and Ti have been investigated. The alloys were produced by vacuum induction melting and subsequent casting in a copper mould. Rapid solidification of the alloys was performed by induction and arc melt spinning processes. A characteristic morphological spacing was measured by the intercept method. The spacing has been compared to calculate values of the secondary dendrite arm spacing. The content of Si seemed to be an important governing parameter in the calculations. An expression for the relationship between the morphological spacing and the cooling rate of Si-rich alloys has been suggested.