Effect of boron on the thermal conductivity and thermal expansion of titanium

Conclusions Additions of boron substantially increase the thermal conductivity of titanium. A linear relationship is observed between the thermal conductivity of titanium-boron alloys and their boron content. It must be emphasized, however, that the rise in the thermal conductivity of these alloys cannot be ascribed solely to the formation of TiB₂ phase. The coefficient of linear expansion of titanium linearly decreases with rise in boron content up to a temperature of 500°C. Above this temperature, a more complex relationship is observed.Translated from Poroshkovaya Metallurgiya, No. 8 (92), pp. 78–82, August, 1970.     

碳化硼(B4C)热导率和膨胀系数及其影响因素分析

热应力是碳化硼芯块在核反应堆使用中破裂的重要原因之一.作者通过检索大量的有关碳化硼热导率和热膨胀系数的文献,搜集了许多经验公式和数据,并与本研究实测值进行对比和分析,得出了一些公式和结果.     

The thermal conductivity of slags used in electroslag remelting

Measurements of thermal diffusivities of solid ESR slags from the system CaF₂ + Al₂O₃ + CaO for temperatures between 200 and 1200°C using laser flash method. Thermal conductivities derived from these data. In the polycrystalline specimens used in this study the radiation conduction is shown to be negligible, heat transfer occurs predominantly by phonon conduction. An appreciable contribution to the thermal conductivity arises from gaseous conduction across pores and microcracks in the specimen. Thermal conductivity decreases with decreasing CaF₂ content.     

脱氮热导法测定钛中氩

钛及其合金对气体元素溶解度高,氩作为保护性气体在钛基材料制备过程中可能进入钛材料从而对其性能产生影响。实验将自制脱氮快速转换装置应用于现有的脉冲热导气体分析仪,转换装置脱氮效率高达97%以上,氮的干扰可量化、可排除,从而实现了钛中氩的准确测定。脱氮热导-程序升温法确定钛中氩可以在1 400 ℃完全释放,氩为非化合态。将脱氮热导法与色谱热导法及飞行时间质谱法对比,氩测定结果一致,因此,脱氮热导法可作为主要参比方法,辅助飞行时间质谱法同时测定金属中氢、氧、氮和氩的新方法建立和完善。     

Thermal conductivity of liquid metals and alloys

The thermal conductivity data of liquid metals have been correlated based on the cell theory of liquids. The temperature dependence of thermal conductivity is predicted in the case of thirteen metals for which experimental data are available. The overall average absolute deviation of predicted values is 4.25 pct. The method has been extended to alloys.     

Experimental evidence for electrochemical nature of the reaction between iron oxide in calcia-silica-alumina slag and carbon in liquid iron

The electrochemical nature of the reaction between iron oxide in calcia-silica-alumina slag and carbon in liquid iron has been studied by measuring the kinetics of the slag-metal reaction. A base slag (48 pct CaO-40 pct SiO₂-12 pct Al₂O₃) containing iron oxide (≤8 wt pct FeO _t ) was reduced by an Fe-C metal bath (∼4 wt pct C) at 1400 °C. The reaction rate was calculated from measurements of the total inlet gas flow rate and the CO concentration in the outlet gas stream. The slag was “internally short circuited” by dipping an iron plate through the slag layer, and this resulted in an increase in the rate of CO evolution. An external circuit was produced by dipping a graphite rod (shielded from the slag) into the metal bath and a steel or molybdenum rod into the slag layer; the open-circuit voltage and short-circuit current were measured when iron oxide was added to the base slag layer. The reaction rate was enhanced by applying a voltage across the slag layer, and an electric arc cathode was employed in some of these “electrolysis” experiments.