Channel-collapse effect examined with laboratory equipment and by two-dimensional calculation

Combustion, Explosion, and Shock Waves -     

Production and use of periclase-chromite concrete parts for the linings of high temperature ladles

Conclusions A method has been developed for production of standard periclase-chromite concrete parts for the linings of high temperature ladles for teeming steel and ferroalloys. The parts have high strength and low porosity and are practically shrinkage-free.The life of periclase-chromite concrete parts in the steel teeming ladles of Chelyabinsk Metallurgical Plant is about four times greater than that of fireclay parts, in Red October Plant practically the same as that observed with the use of high alumina parts, and at Chelyabinsk Electrometallurgical Plant it was higher only in the upper portion of ladles in comparison with that obtained with the normally used fired periclase parts.During service in ladles the parts do not spall, become encrusted at a metal temperature of 1620 °C, do not become encrusted at 1790°C, and at 2200°C are eroded by slag.Translated from Ogneupory, No. 7, pp. 16–20, July, 1982.     

Effect of Quasi-Hydrostatic Compression on the Mechanical Properties of Ceramics in the ZrO2 + 3 MOL.% Y2O3 System

The effect of quasi-hydrostatic compression on the strength of ZrO₂ + 3 mol.% Y₂O₃ ceramic specimens of two series was studied. The series 1 ceramic was a powder commercially available from TOSOH Co. (Japan), with a density of 6.1 g/cm³, and the series 2 ceramic was a powder with a density of 5.9 g/cm³ prepared under laboratory conditions at the IPM Research Institute (National Academy of Sciences, Ukraine). The pressure range was up to 1.2 GPa, and the pressure-transmitting medium was a coarse-grained corundum powder. In the series 1 specimens, the strength increases with pressure over the entire pressure range (from 670 MPa to 1098 MPa at 1.2 GPa); in the series 2 specimens, the strength increases only to a pressure of 0.8 GPa (from 695 MPa to 828 MPa) and then, with further increase in pressure drops sharply to nearly zero (30 MPa at 1.2 GPa). It was proposed that the observed effect might be associated with a martensite transformation in the zone of structural imperfections (discontinuities). On reaching a critical value determined by the strength of the matrix, the martensite transformation becomes a cause of failure of the material.     

Synthesis and characterization of novel aromatic condensation polymers containing rigid benzoxazole pendent groups

A new aromatic diamine monomer containing benzoxazole substituents was prepared by a multistep synthesis starting from 1,4‐dibromo‐2,5‐difluorobenzene. The diamine was polymerized with commercial aromatic dianhydride or dicarboxylic acid chloride monomers to provide several different poly(amic acid)s and polyamides with their inherent viscosities in the range of 0.24–0.46 dL/g. Thermal properties of these polymers including thermal imidization of poly(amic acid)s into polyimides were investigated by using FTIR, DSC, and TGA. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 178–185, 2004     

纤维对莫来石-刚玉质高温窑具性能的影响

莫来石-刚玉质高温窑具是以工业氧化铝和莫来石为主要原料加工而成，材料主要组分为莫来石和刚玉。该窑具具有较高的使用温度（不低于1350℃）、高温强度和化学稳定性，与承烧制品的化学相容性好，特别适用于承烧软磁体（铁氧体）材料和电子绝缘陶瓷。但该材质窑具的抗热震性较差，若提高抗热震性却叉降低了高温强度，存在抗热震性和高温强度之间的矛盾，因此研究了纤维的引入对莫来石-刚玉质窑具性能的影响。     

远红外丙纶的性能研究

系统测试了采用共混纺丝法研制出的远红外丙纶及织物的物理机械性能、远红外发射性能、保温性能、耐洗涤性能和抗菌性能，并对用远红外丙纶加工的护腿的医疗保健作用进行了临床检测。进而讨论了远红外丙纶及织物的医疗保健作用机理。     

单颗粒在浓相悬浮体中的沉降运动

用磁感测量法对颗粒在浓相悬浮体中的沉降过程进行实验研究，得到了悬浮体的表现粘度与悬浮体固体浓度关系及Ars-Lys关系曲线     

Wear of magnesia spinel refractories in portion vacuum-processing steel plant

Conclusions The processes of wear in the lining of vacuum chambers of outdoor-furnace vacuum-treatment plants (UPVS) are due to the simultaneous action of high temperatures, deep vacuum, gaseous medium, molten metal, and slag. The corrosion and erosion of aggressive melts of slag and metal are the decisive forms of wear.Laboratory investigations established the relationship between slag resistance in vacuum and the ratio of corrosive and erosive constituents in the wear of different magnesia-spinel refractories and their phase composition, structure, and properties.Refractories obtained from fused periclase-chromite material with a low content of fusible silicates showed that in laboratory vacuum equipment and during service in the linings of the vaccum chamber of industrial plant they have higher slag resistance and lower wear than refractories based on sintered magnesite, spinel, and chromite ores.Translated from Ogneupory, No. 3, pp. 14–21, March, 1980.     

Determining the enthalpy and specific heat of magnesia spinels in the range 1400–2200°K

Conclusions Temperature functions were obtained for H(T) and C_p(T) which can be used for calculating the thermodynamic functions of the spinels MgAl₂O₄ and MgCr₂O₄ in the temperature regions of their service (up to 2200°K), to supplement the existing relationships (up to 1800°K).Translated from Ogneupory, No. 6, pp. 9–12, June, 1979.