Hydrogen in CuTi and NiTi Metallic Glasses

The hydrogen solubility and its effect on the crystallization of CuTi and NiTi glasses were studied by differential scanning calorimetry, thermogravimetry, and X‐ray diffraction. Dependence of the crystallization products of the hydrogenated Ti‐based alloys on the hydrogen content was found. Whereas in Cu‐Ti alloys hydrogenation leads to drastic decreasing in the thermal stability due to phase separation in the amorphous state and to formation of microcrystalline structure during crystallization, in NiTi system hydrogen produces hydrides with Ni as well with Ti, which after heat treatment decompose, and finally the same crystalline phases as in unhydrogenated alloy are formed. The isothermal crystallization kinetics of the maximum hydrogenated Cu50Ti50 amorphous alloy was also investigated to obtain additional information about this transformation leading to nano‐crystalline material.