Ternary Ti-Ni-Nb alloys have wider transformation hysteresis than binary Ti-Ni alloys. In our experiment, Ti-Ni-Nb alloy was prepared by melting pure titanium , Pure nickel and pure niobium in a cold crucible in a magnertic suspension furnace under a controlled protective argon followed byquenching in an iron mould The hysteresis width under 16% pre-deformation is 155 C. The hydrostatic , tensile, torque, fattigue tests were conducted to evaluate the performance of the pipe coupling system.All the test results indicate excellent behavior and possible applications of Ti-Ni-Nb shape memory alloy in the future .
