Mykhnian O. Obtaining accurate castings of oriented structure of heat-resistant alloys in shell mold of a heat-resistant ceramic

The thesis is devoted to scientific and practical basis for the development of new heat-resistant alloy with high chromium content of nickel-based alloys due to its doping Ta and Re, researching and selecting a thermo and chemically fire-resistant materials to produce shell molds and rods, rational definition of temperature conditions directional solidification blades. The method of mathematical planning of experiments determined the optimal concentration of refractory elements, primarily tantalum and rhenium, and their comprehensive performance in high-temperature alloys with high chromium content of nickel-based alloys, in which significantly increased (1.2 - 1.5 times) resistance material blades to high corrosion without reducing the long-term strength and ductility. We studied the mechanism of the effect of modifiers in the form of dispersed metal powders of aluminum, silicon and boron on the basis of refractory in a multistage process of phase-structural transformations. The effect of sintering temperature on the basis of refractory mixtures of fused quartz and corundum containing different amounts of the modifier for stability of ceramics in molten superalloy. The regularities of the influence of parameters of directional solidification on the dispersion and morphological features of structural and phase components in the alloy developed in the preparation of castings. Based on the results of pilot tests that were carried out in the conditions of the enterprise Gas Turbine Research & Production Complex "Zorya" - "Mashproekt" (Nikolaev), it found that the use of new refractory materials and alloys, as well as technologies and technical solutions developed in the performance of studies allowed reduced by 3 - 4 % flaw casting a burnt, clog and a violation of geometric accuracy for gas turbine blades. For each standard size blades economic benefit of UAH 48 000.