Thermodynamics of boron in a silicon melt

The activity coefficient of B in a Si melt and the interaction parameters of boron and nitrogen in molten silicon were determined by equilibrating solid BN and liquid Si in a nitrogen atmosphere from 1723 to 1923 K. The standard Gibbs free energy change of the nitrogen dissolution into silicon is also obtained. The activities of BO_1.5 in the CaO-CaF₂-SiO₂ and CaO-MgO-SiO₂ systems are estimated in relation to the removal of boron from silicon by these fluxes. Formerly Graduate Student, Department of Metallurgy, The University of Tokyo.     

Determining silicon in alloys of the boron - silicon - carbon system

Conclusions We developed a method for determining the total silicon in alloys in the system boron-silicon-carbon, based on calculating the quantity of silicon by the gravimetric method with preliminary distillation of the boron with a solution of methyl alcohol saturated with hydrogen chloride.Translated from Poroshkovaya Metallurgiya, No. 2 (74), pp. 105–106, February, 1969.     

铁基非晶合金铁硅硼中硅和硼的测定

以相似材质硼铁和硅钢的化学分析方法为基础,建立了氟硅酸钾沉淀滴定法测定铁基非晶合金铁硅硼中硅、酸溶中和滴定法测定铁基非晶合金铁硼硅中硼的方法。硼的测定在酸溶样方法方面进行了改进,即酸不溶的白色絮状物经过滤分离用碱溶液溶解后,与滤液进行合并。硅的测定也将文献方法进行了一些改进,如减少了氢氟酸的用量并直接加入硝酸钾固体促进氟硅酸钾沉淀完全。本方法与传统方法硅和硼的检测结果相符,且重复性较好。     

Sintering of iron—silicon—boron magnetically soft steels

An investigation of structure formation in multicomponent magnetically soft powder metallurgy steels was carried out. A model for the homogenization of Fe?Si-0.06% B alloys over a wide range of silicon concentrations is proposed. The optimal processing regime was determined. Highest magnetic induction was obtained in a 1% Si alloy, and highest permeability in a 6.5% Si alloy (both are sintered at 1300°C for 6 h).     

Compressive property of liquid silicon (infiltrated) boron carbide

Compressive deformation of reaction bonded boron carbide has been carried out over a strain rate range 10⁻⁴ to 10⁻² s⁻¹. The maximum compressive strength of reaction bonded boron carbide at strain rate of 10⁻⁴ s⁻¹ is 370 MPa and 470 MPa at strain rate of 10⁻² s⁻¹. It is not possible to carryout quasi-static compression test at very higher strain rates (≥ 10² s⁻¹). However, the data generated at low strain rates can be extrapolated to higher strain rates and this data correlate well with the experimental compressive strength values generated by dynamic compression tests.     

吹氧条件下铁液中硅和硼的氧化规律

研究了吹氧条件下Fe-C熔体、Fe-C-Si熔体、Fe-C-B熔体和Fe-C-Si-B熔体中碳、硅、硼的氧化规律,实验在中频感应炉中进行,实验温度为1 450±25 ℃.结果表明:含硼生铁中硅和硼首先氧化,达到一定程度后碳才开始氧化;含硼生铁中硅、硼氧化是同时进行的,相互影响.     

Composites with zirconium matrix reinforced with boron and silicon carbide fibers

Structural features of a composite material (CM) consisting of a plastic zirconium foil-like matrix reinforced with continuous high-strength fibers of boron or silicon carbide with a diameter of 100 μm (25 to 30 vol.%) are examined at testing temperatures up to 950 °C. Model specimens are compacted by diffusion welding in vacuum at 1100 °C. Structural studies reveal a diffusion interaction area at the fiber-matrix interface. Cracks and pores appear in the area at 1100 °C. The effect of the diffusion area thickness on CM mechanical properties is discussed. It is established that reinforcement of zirconium with B or SiC fibers provides 7 and 5 times higher strength at 950 °C, respectively. __________ Translated from Poroshkovaya Metallurgiya, Vol. 46, No. 1–2(453), pp. 48–53, 2007.     

Grain boundary segregation and grain growth inhibition in silicon iron: The effect of boron and nitrogen

The degree of grain growth inhibition in iron-3.1 pct silicon alloys with small additions of boron, nitrogen and sulfur has been observed to correlate strongly with the degree of nitrogen segregation to the grain boundaries. Grain growth was seen to increase monotonically with decreasing nitrogen segregation at 950°C, the temperature at which significant grain growth was first observed to occur. Boron affected the retention of nitrogen in the material at high temperatures and in this way had an indirect effect on grain growth inhibition. Sulfur acted to enhance the effectiveness of nitrogen as a grain growth inhibitor. It is suggested that nitrogen, even at very low grain boundary concentrations affects grain boundary migration by poisoning sites at the grain boundaries which are particularly efficient in attaching atoms to the growing grain surface. This paper is based on a presentation made at a symposium on “Recovery, Recrystallization and Grain Growth in Materials” held at the Chicago meeting of The Metallurgical Society of AIME, October 1977, under the sponsorship of the Physical Metallurgy Committee.