Regular relief on a silicon surface as a structural defect getter

An investigation was made to determine how a regular relief on the silicon surface influences gettering in silicon-silicon-dioxide structures. The regular relief was created by a photolithographic technique before oxidation and comprised an orthogonal network of overlapping bands. The gettering was determined from the isothermal relaxation of the capacitance of a silicon-silicon-dioxide structure after switching from strong inversion to even stronger inversion. It is shown that a regular relief at the silicon-silicon-dioxide interface is an effective getter at a depth of several hundred micron. Pis’ma Zh. Tekh. Fiz. 25, 75–80 (January 12, 1999)     

Effect of heat treatment on the structure and properties of a high-nitrogen austenitic corrosion-resistant 03Kh20AG11N7M2 steel

The structure and mechanical and corrosion properties of a high-strength austenitic 03Kh20AG11N7M2 steel after quenching and aging at 500 and 800°C are analyzed. The phase composition of the steel and the mechanism of the decomposition of austenite during heat treatment are studied by electron-probe microanalysis and transmission electron microscopy. This steel is thermally stable upon heating to 800°C for 1 h and is stable to the γ → α and γ → ɛ martensitic transformation during deformation up to tensile strains leading to fracture. The homogeneous decomposition of a supersaturated γ solid solution at 500°C leads to the formation of disperse CrN nitrides, which increase the strength of the steel and insignificantly decrease its plasticity. In this case, the stress corrosion cracking resistance slightly decreases and the passivation of the steel increases in an corrosive medium without loading.     

Ultrafast turn-off of high currents by field-controlled integrated thyristor

The turn-off process in a powerful high-voltage switch of the new type, integrated thyristor controlled by an external MOSFET, has been studied. Dynamic characteristics were measured in high current turn-off regimes, in which plasma is removed by the full device current. The limiting density of switched current amounted to 600 A/cm². The regime with short circuit of several dozen thousand parallel operating microthyristor cells is quite effective, ensuring a current decay time of about 40 ns, which is several times as small as that in all other types of high-voltage switches for working voltages above 1.5 kV.     

Influence of rare-earth metals on the high-temperature strength of Ni<Subscript>3</Subscript>Al-based alloys

The influence of the content of reaction- and surface-active alloying elements (rare-earth metals (REMs)) and the method of their introduction into cast high-temperature γ′-Ni₃Al-based intermetallic alloys, which are thermally stable natural eutectic composites, on their structure-phase state and the mechanical properties is studied. The life of low-alloy heterophase γ′ + γ cast high-temperature light Ni₃Al-based alloys is shown can be increased at temperatures exceeding 0.8T _m (T _m is the melting temperature of Ni3Al) due to additional stabilization of the single-crystal structure of these alloys with submicron and nanometer-sized particles of the phases formed by refractory and active REMs. It is also shown that stage-by-stage fractional introduction of all components into alloys during vacuum induction melting with allowance for their reaction activities (most refractory metals are introduced in the form of low-melting-point master alloys at the first stage of vacuum induction melting, and lanthanum is introduced with a master alloy in the optimal contents of 0.1–2 wt % into the charge of VKNA-1V and VKNA-25 alloys at the final stage) leads to the formation of a modified structure stabilized by nanoprecipitates of nickel and aluminum lanthanides and the phases formed by refractory metals. This method increases the life of VKNV-1V-type alloys (0.5 wt % Re) at 1000–1200°C by a factor of ∼1.7 and that of VKNA-25-type alloys (1.2 wt % Re and Co) by a factor of ∼3.     

Reduction of cracking in refractory structures of thermal setups

The development of fracture in a large-size lining of coke banks at the Stakhanov Coal-Tar Plant was studied. The main parameters of crack formation and the lining zones most susceptible to cracking were determined. A method of preventing the development of cracking in these zones is suggested that is based on the use of crack compensators, formed on the surface of lining blocks, favoring accommodation of temperature-induced deformations. Translated from Ogneupory i Tekhnicheskaya Keramika, No. 3, pp. 35–37, March, 1997.     

Influence of Modes of Thermoplastic Treatment on the Development of Microplastic Strain in Nitrogen-Bearing Steel Kh21G10N7MBF

The effect of the degree of reduction in cold rolling and subsequent heat holds on the development of microplastic strain in the bending of ribbon specimens fabricated from corrosion-resistant austenitic high-nitrogen steel Kh21G10N7MBF is studied.__________Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 2, pp. 3 – 6, February, 2005.     

Modified chemisorptive fibres based on a copolymer of acrylonitrile with 5-vinyl-2-methylpyridine

Conclusions Conditions for the preparation of salt forms of a chemisorptive fibre based on a copolymer of acrylonitrile and 5-vinyl-2-methylpyridine have been worked out.It has been found that the formation of stable salt forms of the copolymer is determined by the basicity of the pyridine groups.The effect of the basicity of the functional groups and salt forms of the polymer on the equilibrium and kinetic characteristics of fibres in the sorption of gases of acid or basic character has been shown.Translated from Khimicheskie Volokna, No. 1, pp. 22–24, January–February, 1988.