Influence of Oxidation on the Properties of Near-Surface Layers of Metals from Group IV (Ti, Zr, and Hf)

We present characteristics of near-surface layers of d-elements from group IV (titanium, zirconium, and hafnium) after diffusion saturation from a controlled oxygen-containing gas medium ( T = 750°C, τ = 5 h under P = 1.33·10 –1 Pa, 1.33·10 –2 Pa, and 1.33·10 –3 Pa). It is shown that a hardened diffusion layer without phase film whose hardness is higher than the hardness of the metal matrix is formed in the order inverse to the order of the affinities for oxygen. The differences in the outward appearance of the surfaces of samples prior to and after heat treatment are demonstrated.