Influence of Ti on the hydrogen-induced phase-structure transformations in the ZrCr2 intermetallic compound

The effect of hydrogen—Hydrogenation, Disproportionation, Desorption, Recombination (HDDR) process—for Zr1−xTixCr2 (x=0.1, 0.2) alloys on their phase–structure transformations has been investigated by means of differential thermal analysis (DTA) and X-ray diffraction (XRD) at an initial hydrogen pressure of 5 MPa and the temperature range from room temperature to 960 °C. The formation of hydride in Zr1−xTixCr2–H2 systems was registered within the temperature range from room temperature to 415 °C by DTA. The hexagonal C14 type Laves phase of the initial Zr1−xTixCr2 (x=0.1, 0.2) alloys starts to decompose at 3–5 MPa and at temperatures of 890–960 °C forming the original alloys, ZrHx hydrides and Cr. The compounds decompose completely into zirconium and titanium hydrides and chromium at 960 °C in hydrogen under P H 2 = 5 MPa after 4–17 h holding time. Recombination of the alloys has been carried out by heating in vacuum to 920–960 °C and holding at the highest heating temperature for about 3 h. The C14 and C15 type Laves phases or their mixture are the main recombined products.