Intermetallic compound formation in the Zr–Al–Si ternary system

The microstructure and composition of binary and ternary intermetallic compounds have been studied in a ternary diffusion couple of Zr and Al–Si eutectic alloy. The τ1 and τ3 phases always formed in the liquid part of the diffusion couple and τ2 phase formed as a layer structure. Two intermetallics, ZrSi and ZrSi2, of the Zr–Si binary system have been observed. A number of intermetallics, namely, ZrAl3, ZrAl2, Zr2Al3, ZrAl, Zr3Al2, Zr5Al4, Zr5Al3, Zr2Al and Zr3Al, of the Zr–Al system have been observed. The solubility of Si in the ZrAl3 and ZrAl intermetallics is very small. In the other intermetallics, the solubility of Si is negligible. The results of this investigation also show two ternary invariant reactions. The microstructure of a number of phases has been presented.