Polytypic transformations of the HfCr2 Laves phase - Part I: Structural evolution as a function of temperature, time and composition

► The Hf-Cr system was reinvestigated in the HfCr2 Laves phase region. ► The C14 polytype stable above 1420 °C transforms to C36/C15 at lower temperature. ► The heavily faulted transformed states contain C14/C36/6H/C15 intergrowths. ► The transformed states exhibit thus complicated diffraction patterns. ► The faulting is a consequence of the phase transformation starting from C14.