Abstract: The variations of Debye temperature and lattice parameter of Ti-30Mo alloy with different hydrogen contents were measured by means of X-ray diffraction.It was found that as the hydrogen content increases,the Debye temperature decreases,but the lattice parameter of the aUoy increases.The above results experimentally support the decohesion theory that the in- crease of hydrogen in metals will weaken the cohesive force between the atoms and make met- als brittle.

Key words: Debye temperature, lattice parameter, lattice decohesion theory, Ti alloy