Influence of a boron.on heat resistance of the titanium and its alloys

Influence of 1.2 % B on the heat resistance of titanium and titanium alloys at the temperatures of 600-1000 degrees C during 50 h is studied. As shown, boron renders the negative influence that manifests itself in degradation of heat resistance due to the formation of fusible boron oxide. In this connection, an effect of alloying by Al, Zr and Si on the reduction of boron bad influence is studied. As revealed, the oxidation rate for titanium alloys is controlled by diffusion processes with the imaginary activation energy of 140 kJ/mole and does not depend on composition up to 9000 degrees C. At more high temperatures, the activation energy is 340 kJ/mole due to the transition to another kinetic dependence. The formation of scale as a mixture of oxides and the forming.frail layer of oxygen solid solution in titanium are results of oxidation of these alloys. An alloying of Ti-1.2 B alloy by aluminium, silicon and zirconium allows to govern both the formation of a scale and the thickness of titanium layer saturated by an oxygen due to their influence on the diffusion-processes' rate and the enhancement of scale protective properties.