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The crucibles containing a significant amount of crystalline graphite as one of the refractory components are used in a number of induction crucible furnaces [I]. The produc tion technology of the crucibles involves maxing of the initial (raw) components, shaping the body using one technique or other, and firing [2].The composition and the dispersion of the original body, its moisture content, and the production technology of the crucibles (the mode of compaction and the firing conditions) determine the structure of the material of the crucibles and the degree of uniformity (homogeneity) throughout the volume which, in turn, determine the properties.In order to calculate the thermal and electrical parameters, to determine the main parameters of the induction crucible furnaces, and to evaluate the structuraluniformity of the crucibles, it is necessary to study the properties of the material (such as density, thermal conductivity, and electrical resistance) in different parts (zones).In view of this, we studied the properties of three types of graphite-containing crucibles. Table i gives the basic information regarding these crucibles.According to the data of x-ray structural analysis* of the specimens subjected to technological heat treatment and subsequently used for determining the property indices, the material of the TKG crucible contains graphite and silicon carbide B-SiC as the main components, the material of the TGG crucible contains graphite, ~-cristobalite, and mullite, and the material of the TGN crucible contains graphite and silicon.In order to evalaute the effect of structural nonuniformity of the material of the crucible on its properties, specimens were taken from different parts (zones) of the crucibles (Fig. i) and their thermal conductivity and electrical resistance were measured.For carrying out thermal conductivity measurements, 10-mm-thick plate-specimens in the form of squeres having a side of 85 mm were cut out parallel to the working surfaces of the crucible: from the side walls, specimens were taken in the immediate vicinity of the external surface after removing the glaze layer and from the base, specimens were taken in the regions close to the internal surface.In order to conduct the measurements of electrical resistance, specimens were cut out in the form of prisms having a cross section of I0 • i0 mm and a height of 25-30 mm in the directions perpendicular to the side wall and the base of the crucible.

Metal-Insulator-Metal Capacitor (MIMC) reliability and electrical properties are defined by the TDDB lifetime, breakdown voltage and leakage current. This article demonstrates the correlation between these electrical properties and the physical properties of the dielectric layer. The intrinsic quality of MIMC capacitors can therefore be predicted before complete processing by measuring a physical property of the MIMC dielectric.

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shakova, O. M. Kostenok, and A. M. il'in UDC 666.762.81.017:536.21 Carbon-graphite materials are widely used in various branches of industry. At present there have appeared a number of new carbon-base thermal insulation materials, the area of use of which is difficult to determine without a preliminary study of their properties. This work was done for the purpose of investigation of the thermal conductivity in various gaseous media of the new materials, basic information on which is given in Table i.As the result of the limited temperature and amount of experimental investigation an attempt was made to use earlier developed [i] calculation methods for determination of the thermal conductivity of the materials at temperatures up to 2000=C in various media. The calculations also make it possible to determine the thermal conductivity of materials of different density with a gas pressure differnt from atmospheric. Since the calculation methods were developed for other groups of materials, use of them for reliable determination of the thermal conductivity of carbon-graphite materials, including fiber ones, requires accumulation of a sufficient quantity of experimental data and subsequent development of calculation methods aided by the work done.