THE SC-NI SYSTEM

The Sc-Ni system was reinvestigated because of the need of more accura te data for the study of the phase equilibria of the Sc-Ti-Ni ternary system. Sc-Ni alloys melted from the components were characterized usi ng X-ray, metallographic, differential thermal and electron microprobe analyses. In contrast to the former diagram of the Sc-Ni system, the Sc,Ni phase is formed by the peritectical reaction L + delta reversibl e arrow eta at 990 degrees C. It was found that the transformation in the scandium-based alloys occurs via the metatectic reaction beta reve rsible arrow L + alpha (where alpha is the hpc and beta the bce modifi cation of scandium) at 950 degrees C. The eutectic reaction, L reversi ble arrow Sc2Ni + alpha(Sc), takes place at 840 degrees C. As a result of the study of the Sc-Ni system the binary phase diagram was constru cted. (C) 1997 Elsevier Science S.A.