According to the ni-ti binary phase diagram and the constituent phases reported in the microstructure of as-cast ………… phase has loe-west decomposition temperature…………. compared to the other phases present of the cast alloy therefore the maximum treatment temperature of the as- alloy was predetermined to be…………… lower than the melting point of an arc melted ingot was sectioned to produce these samples using electrical discharge machining these samples were sealed in quartz tubes which were evacuated and backfilled with high-purity argon gas in order to avoid oxidation the sealed a=samples were heated at different temperatures ranging from…………….. and held for differ-Ent times between and then rapidly removed and quenched into water at room temperature