材料期刊网

In this work, Ti-50.6 at.% Ni shape memory alloy were solution annealed at 800 degreesC for 20 min and quenched in icy water, further annealing were done at 380 degreesC for 1 h, and then irradiated with 1.7 MeV electron at the fluence of 3.2 x 10(20)-12.8 x 10(20) m(-2). The evolution of transformation temperatures was studied by differential scanning calorimeter (DSC). Effect of annealing on the evolution of multiple-step transformation temperatures also investigated. Heat treatment and irradiation had a prominent effect on the transformation, but with different characteristics. The M-1 (the first R-phase --> martensite transformation) showed little change after irradiation, but the M, (the second R-phase --> martensite transformation) transformation temperature decreased with increasing electron fluence and disappeared at the fluence of 12.8 x 10(20) m(-2). Heat treatment causes the shift of R-phase transformation start/finish temperature (R-s/R-f) to lower temperature and the shift of M-1 and M-2 transformation temperatures to higher temperature. The peaks of M-1 and M-2 almost merged into one peak with increasing annealing temperature. The effects of irradiation and annealing on the transformation characteristics are not exchangeable, so irradiation is also an important method for the study of condensed matter. (C) 2003 Elsevier B.V. All rights reserved.