Dynamics of nanopore structure formation in the carbonization of carbon-containing materials

The dynamics of nanopore structure formation in the carbonization of carbon-containing materials with various volatile matter contents was determined using physicochemical methods of analysis. The main stages of the formation of the nanopore structure of carbon adsorbents upon carbonization were demonstrated.     

Infrared Spectra and Structure of Si3N4, Si2ON2, and Sialons

Sialon powders are prepared from Kyshtymskoe kaolin with 12 – 28 wt.% carbon mixtures by the carbothermal reduction-nitridation method. The infrared spectra of -, O-, C- and 15R-phases in the Si – Al – O – N system are recorded and compared with the IR spectra of Si₃N₄, Si₂ON₂, and kaolin. The IR data are shown to correlate with the chemical composition of sialons and provide information supplementary to x-ray phase analysis data. The spectra of sialon powders differ from each other and from the spectrum of silicon nitride.     

Plasma erosion opening switch for fast discharges with current growth rate about 10<Superscript>12</Superscript> A/s<Superscript>1</Superscript>

The article presents the construction of a plasma erosion opening switch, capable of creating the discharge with electrical current of several tens kiloamperes and a growth rate up to 10¹² A/s in the circuit with the inductive load up to 100 nH. The results of test experiments with imitator of load are presented. The discharge circuit under consideration will be used for the experiments for creation of shock waves in plasma.     

Study of a 44NKhMT precision powder alloy produced from nanopowders

Properties of elinvars produced by a powder technology are studied experimentally at all hierarchic structural levels. The problems of an increase in the homogeneity of the structure and a decrease in the porosity of a powder elinvar are solved by alloying with titanium hydride and 2 wt % nickel powder with a particle size of 50–70 nm. A heat treatment regime is optimized to improve the mechanical properties, namely, the hardness, strength, modulus of elasticity, and porosity. Based on the studied laws of structure formation, a powder elinvar with properties similar to the corresponding cast alloy is produced: its density is 98%, the modulus of elasticity is up to 190 GPa, the ultimate strength is 1100 MPa, and the relative elongation is up to 13%.     

Effect of fine crinding on the structure and properties of zirconia

The effect of fine grinding on the properties of ZrO₂ powders is investigated, and the peculiarities of the formation of the structure of materials from mechanically activated ZrO₂ powders are considered. Disintegrator processing of powders increases the reaction ability in sintering, stabilizes the crystal structure of the material, and ensures higher mechanical characteristics of the ceramics.Translated from Ogneupory, No. 2, pp. 2 – 4, February, 1994.