[en] Coatings produced by electric-spark alloying of molybdenum tungsten and steels with lanthanum hexaboride or with LaB₆-base alloys (with Co, Ni, Mo additives) are studied for their thermoemissive properties. Work func-- tion of the coatings slightly differs from that of LaB₆ proper, though small amounts of the LaB₆-base phase are present in the coating and the phase accompanies the basic constituent M₂B (Me is the substrate metal)

[en] On Fe₄₀Ni₄₀P₁₄B₆ specimens amorphous alloy pouder crystallization is analyzed to show that the heat absorption effect at the precrystallization stage may be described from the standpoint of a new phase growth in the elastic medium. The increase in thermal stability of amorphous powder materials is associated with high vitrification temperatUre, dispersivity and high surface tension valUe. These factors should be taken into account when choosing compacting conditions for amorphous alloy powders

[en] A comparative study of low-temperature alloy formation is carried out in the W-Mo composite whose production follows three different schemes: mixing of the W and Mo powders, reduction of the mechanical WO₃-MoO₃ mixture, reduction of the preliminary-produced complex oxide (Mosub(0.5)Wsub(0.5))Osub(3). It is shown tht in the third case an ideal homogeneous alloy can be produced at a rather low temperature (approximately 800 deg C) directly as a result of reduction

[en] Temperature dependence of resistivity, heat conductivity and thermoelectric coefficient is studied for niobium carbide NbCsub(0.82) single crystals of high purity and perfection degree. Single-crystal niobium carbide is shown to be characterized by a higher electric resistance as compared with polycrystalline one

[en] Structure of sintered tungsten, deformed by a hot rolling is studied experimentally. It is shown that a microstructural heterogeneity is always formed in the process of hot tungsten rolling with introducing a transverse direction at a certain stage of cogging, on wedge-shaped laminas and during uni-directional rolling. It is also shown that formation of enlarged microstructure elements is of deformational origin. Possible reasons of macrostructural heterogeneity are discussed. Recrystallization able to accompany hot deformation is noted to be of a more local character

[en] A method of solid phase voltammetering with a carbon paste electrode is applied for the phase analysis of powders in the GdB₄-GdB₆ system. It is shown that the method may be used for proximate analysis of the single-phase structure of gadolinium boride powders

[en] Results of structural analysis for hard tungsten-cobalt alloys are presented. They are obtained by automatic image analyser ''Quantimet-720'' and a complex of computer processing programmes. It is shown that data on the structure allow considering quantitatively the effect of tungsten carbide grain size on crack resistance of hard alloys as well as singling out those grades for which it may be increased

[en] A projection of solidus surface is plotted for the partial Ru-ZrRu-ZrIr-I) system. It is shown that ternary compounds are not formed in this system. Isostrucutural ZeRu and ZrIr phases form a continuous series of solid solutions. A high reciprocal solubility of ruthenium and iridium is observed both in primary solid solutions and in intermediate ZrRu₂, ZpIr₂ and ZrIr₃ phase (from 0.29 to 0.5%). Four triphase fields exist at subsolidus temperatures: < Ir > + < Ru > + < ZrIr₃ >, < ZrIr₃ > + < ZrIr₂ > + < ZrRu₂ >, < ZrIr₂ > + < ZrRu₂ > + Zr(Ru, Ir) and < Ru > + < ZrIr₃ > + < ZrRu₂ > as well as nine duel phases corresponding to them. Temperatures of the melting start for the Ru-ZrRu-ZrIA-Ir system alloys decrease to the Zr-Ru side of the concentration triangle

[en] It is shown possible to produce certain heat-resisting coatings on graphite by plasma spraying. A diagram of the device for a qualitative estimation of the coating for thermal stability using a plasmatron for spraying is given. The procedure developed may be recommended as a proximate method for estimating thermal stability of heat-resisting coatings applied to graphite and other structural materials according to the plasma spraying technique

[en] Distinctive properties of strain hardening and failure of powder iron were studied as compared with compact material. To analyze strain hardening powder iron specimens with different porosity (6-24%) and cast armco iron were used. Coordinates σ=f (e¹¹²) (where σ-stress, e-effective strain) show that hardening curves with an increase of the porosity arrange one under another and have no breaks typical of the compact material. The deviation is stated to be due to loosening of the material in the process of plastic deformation. Loosening is followed by a respective increase (approximately 4%) of porosity. Repeated standardization of the hardening curves taking into account the factor of the material loosening during deformation leads to their complete coincidence. It is stated that regularities of the powder iron strain hardening with allowance for its initial porosity, strain concentration and loosening during deformation are comparable between themselves and compact material