The Effect of Minor Elements on Exothermic Fusion Reaction to Form a Ti-Ni Intermetallic Compound

　A Ni-Ti intermetallic compound has been obtained easily by exothermic fusion reaction under the adequate condition of rapid heating under low pressure, although the heating temperature does not reach the eutectic point for a Ti-Ni alloy. The exothermic fusion reaction of a Ni-Ti powder compact happened accompanying the reaction of minor elements with each other, which Ti powder contains: Na, Mg, Cl, O, H. B and Si added to a Ni-Ti powder compact trigger a more active exothermic reaction than the minor elements which are included in raw Ti particles. The ignition of the reaction by the contained or added elements affected the temperature and the reaction time when the self-exothermic reaction of a Ni-Ti compact started rapidly.