Effect of carbon treatment on surface hardening of TiY–TZP

A powder of TiO 2–Y 2O 3–ZrO 2 solid solution was prepared by the coprecipitation-calcination technique. Its sintering at 1400 °C lead to the dense material composed mostly of the tetragonal symmetry phase. Samples of these material were inserted into a carbon bed and heat treated at 1650 °C in Ar atmosphere. Titanium carbide inclusions in the form of elongated particles were precipitated in the near surface layer of the material. Its surface hardness increased essentially.