Thermomigration Kinetics in the Si–Al–Ga and Si–Al–Sn Systems

The thermodynamics and kinetics of the thermomigration of molten zones based on Al–Ga and Al–Ga melts in the preparation of silicon epilayers have been studied in detail. We have determined the threshold thermomigration temperature for zones of various compositions. The migration onset temperature has been shown to increase monotonically with increasing Ga or Sn concentration in the liquid phase. The thermomigration rate of Si–Al–Ga zones decreases with increasing gallium concentration at temperatures below 1473 K and increases at higher temperatures. The thermomigration rate of Si–Al–Sn zones decreases with increasing Sn concentration over the entire temperature range studied. No chemical compounds have been detected in the Si–Al–Ga or Si–Al–Sn system, which simplifies the use of the thermomigration method in these systems.     

Simulation of Structural Transformations in Heating of Alloy Steel

Metal Science and Heat Treatment - Amathematical model for computer simulation of structural transformations in an alloy steel under the conditions of the thermal cycle of multipass welding is...     

Study of the formation of contact between rough surfaces based on the particle method

A model is proposed for the rough surface of a solid based on the particle method. Although the particle size is selected arbitrarily in this study, the evolution of the actual area of contact and the change in stress at the points of contact show fairly good agreement with concepts derived from experimental investigations. The experiments show that as two surfaces converge, the pressure at the contacts is considerably higher than the nominal value, and this leads to plastic deformation of the surface layers much greater than the bulk deformation. The model clearly shows the controlling factors and how the stressed state of the surface layer is formed. The model can be used to analyze interaction between surfaces, not only for the stationary case, but also when these undergo relative displacement. Pis’ma Zh. Tekh. Fiz. 24, 28–32 (March 12, 1998)     

Study of plastic shear deformation in surface layer at friction. Simulation results. Part I. Model description

A one-dimensional macroscopic model of friction is presented which considers changes in elastic characteristics of the material caused by frictional heating and strain hardening. A single act of contact between a microasperity made of a ductile hardenable material and the counterbody was calculated for various contact spot sizes. It is shown that the contact spot size affects considerably the temperature, plastic deformation, and changes in the material elastic characteristics. Shears of surface layers relatively to the base material observed experimentally are explained proceeding from the modeling results.     

Numerical study of the effects of heterogeneous recombination and heterogeneous initiation on flame propagation in hydrogen-air mixtures at atmospheric pressure

Two-dimensional numerical simulation of th e effect of heterogeneous recombination ad heterogeneous initiation reactions on flame propagation in hydrogen-air mixtures has been carried out for different types of boundary conditions and different fuel-to-oxidizer ratios at atmospheric pressure.     

Potential efficiency of data transmission systems in channels with non-Gaussian quasi-pulsed interferences

The potential efficiency of data transmission systems in channels with quasi-pulsed radio interferences of the natural and industrial type has been estimated. The lognormal model of pulsed interference components has been used.     

Using acoustic emission for the analysis of wear processes during sliding friction

The acoustic response of two friction pairs, in which brittle fracture and intense plastic deformation take place during friction, has been studied. The acoustic signals have been analyzed by calculating median frequencies using the window Fourier transform technique.