Determining maximum capacity of an autothermal fluidized-bed gas generator

The characteristics of a self-heated gas generator are simulated and investigated experimentally. The maximum capacity and optimal parameters of this installation are determined.     

Adjusting the linear expansion coefficient Lin Fe-Ni-Co-Ti invars by aging and phase hardening

The N30K10T3 and N40K10T3 invars with the Curie points θ_C ≈ 200°C and θ_C ≈ 310°C and the martensite temperatures M _s ≈ −80°C and M _s < −196°C, respectively, have been studied. The two alloys were hardened by quenching in the range of temperatures from 100 to 750°C. In addition, the first alloy was hardened by a combination treatment including phase-transformation-induced hardening and aging. The method of phase hardening consisted in the use of a forward (γ → α) and a reverse (α → γ_ph) martensitic transformations. It has been shown that the temperature dependences of the linear expansion coefficient and the dependences of the hardness on the temperature and time of aging are considerably different for both alloys upon decomposition of the supersaturated solid solution. Both the ordinary and the double aging have been studied.     

Promising method of producing cast billets from superalloys

A new method is proposed for electroslag casting of products made of superalloys. A melt is modified by ultradispersed refractory particles, and the accumulation of a metal in a melting vessel and its pouring into a mold are performed in an argon atmosphere. The equipment designed for this method is described. The results of comparative analysis of the properties of the cast metal are presented, and the advantages of the method are shown.     

Acoustic investigations of Ga-Pb miscibility gap melts

The ultrasound velocity is measured in Ga-Pb melts from the monotectic temperature to 1100 K over the entire concentration range by a pulsed-phase method. Anomalies are detected in the temperature dependences of the ultrasound velocity near the critical point. The boundary of the miscibility gap is determined from the results of acoustic measurements. The miscibility gap temperatures measured by the acoustic method agree well with the reported data.     

Effect of terbium gallium garnet crystal orientation on the isolation ratio of a Faraday isolator at high average power

We present a comprehensive and systematic investigation of the fundamental physical limitations of Faraday isolation performance at high average powers that are due to thermally induced birefringence. First, the operation of various Faraday isolator designs by use of arbitrary orientation of cubic magneto-optic crystals is studied theoretically. It is shown that, for different Faraday isolator designs, different crystal orientations can optimize the isolation ratio. Second, thermo-optic and photoelastic constants for terbium gallium garnet crystals grown by different manufacturers were measured. Measurements of self-induced depolarization are made for various orientations of crystallographic axes. The measurements are in good agreement with our theoretical predictions. Based on our results, it is possible to select a crystal orientation that optimizes isolation performance at high average powers, resulting in a 5-dB enhancement over nonoptimized orientations.