The effect of alloying additions on the emissivity of titanium in the neighborhood of polymorphous transformation

The results are given of measurements of the integral emissivity of alloys on the basis of titanium alloyed with aluminum and vanadium. The behavior of the polytherm of emissivity in the neighborhood of polymorphous transformation is treated, as well as the temperature dependence of emissivity in the region of the $\beta$-phase. The method of electronic heating under conditions of oilless vacuum is used to investigate the temperature-related features of the emissivity of titanium alloys in the temperature range from $1100$ to $1700$ K. The effect of the concentration of aluminum and vanadium on the emissivity of titanium is discussed. It is demonstrated that the presence of aluminum as an alloying element which stabilizes the $\alpha$-phase extends the temperature range of polymorphous transformation and increases the absolute values of integral hemispherical emissivity. On the contrary, the presence of vanadium as the stabilizer of the $\beta$-phase "narrows down" the temperature range of polymorphous transformation and causes a decrease in the temperature in this range. Approximating equations are given for all of the investigated alloys in the region of the в-phase. The obtained results are compared with the available data. The limiting relative experimental error is estimated at $2.5\%$.