Two-stage B2-B19-B19′ martensitic transformation in a Ti50Ni30Cu20 alloy observed by synchrotron radiation

Direct X-ray diffraction experiments with an intense synchrotron radiation beam were carried out, to confirm whether or not the successive B2-B19-B19′ transformation occurs in a solution-treated Ti50Ni30Cu20 alloy. Consequently, the second B19-B19′ transformation was found with Ms = 192 K. The lattice parameters of both martensites were also determined as a function of temperature.