EFFECTS OF HOT-ROLLING ON THE MARTENSITIC-TRANSFORMATION OF AN EQUIATOMIC TI-NI ALLOY

Rolling temperature and thickness reduction are important influences on the work hardening and hardness of hot-rolled plates. Transformation temperatures are inversely proportional to the hardness of cold-rolled specimens. At rolling temperatures greater-than-or-equal-to 600-degrees-C, partial recovery or recrystallization affect the work hardening rate, but not the proportional constant K. However, K can be affected by different processes, such as hot rolling or thermal cycling. Experimental results show that the B2 --> R-phase transformation can be induced by severe deformation at lower rolling temperatures and that hot-rolled Ti50-Ni50 alloy still undergoes a natural thermoelastic martensitic transformation.