Preparation of the (Zr,Mo)B2 solid solutions through the reduction of oxide solid solutions

Abstract

Three methods (boron reduction, boron carbide reduction and boron carbide with carbon black reduction) were used to synthesize zirconium-molybdenum diboride. The use of pure boron as a reducing agent led to obtaining pure crystallites of (Zr, Mo)B2 using a size of 0.5–0.7 μm. While using the B4C as a reduction agent, two cases were possible. When the Zr:B ratio was less than 1:2, unreacted ZrO2 was observed in the synthesized material. At the same time, when the ratio was 1:2 the inclusion of B4C was found. The average grain size of (Zr, Mo)B2 was 1–3 μm. However, the use of a combined reducing agent B4C and C leads to the formation of the (Zr,Mo)C phase, which does not allow obtaining a homogeneous solid solution based on zirconium diboride. The formation of pure solid solution is possible when the amount of Mo equal 6 at%.