The ternary system nickel-boron-silicon

The ternary system Nickel-Boron-Silicon was established at 8500C by means of X-ray diffraction, metallographic and micro-hardness examinations. The well known binary nickel borides and silicides resp. were confirmed. In the boron-silicon system two binary phases, SiBsub(4-x) with x approximately 0.7 and SiB6 were found the latter in equilibrium with the β-rhombohedral boron. Confirming the two ternary silicon borides a greater homogeneity range was found for Ni6Si2B, the phase Nisub(4,6)Si2B published by Uraz and Rundqvist can better be described by the formula Nisub(4.29)Si2Bsub(1.43). In relation to further investigations we measured melting temperatures in ternary Ni-10 B-Si alloys by differential thermoanalysis. (author)