Phase relations in the Nd-Al-Si system at 500 degrees C

The partial isothermal section of the phase diagram of the Nd-Al-Si ternary system at 500 degreesC (50 at.% Nd or less) has been investigated by X-ray diffraction analysis, differential thermal analysis, scanning electron mic roscopy and electron micro-probe analysis. The existence of six binary comp ounds, alpha Nd2Si3, beta NdSix (x less than or equal to1.8 less than or eq ual to2.0), NdAl, NdAl2, NdAl3 and alpha Nd3Al11, and three ternary compoun ds, NdAl2Si2 (gamma), NdAl1.75Si0.25 (delta), NdAl1.25Si0.25 (eta), was con firmed. The ternary compound NdAl1.5Si0.5 was not found in this section. Th is isothermal section consists of 11 single-phase regions, 21 two-phase reg ions and 11 three-phase regions. The compound NdAl1.25Si0.25 has a large ho mogeneity range, while the other ternary compounds are non-solubility compo unds. (C) 2001 Elsevier Science B.V. All rights reserved.