Structure and Properties of Heat-Resistant Alloys NiAl–Cr–Co–X (X = La, Mo, Zr, Ta, Re) and Fabrication of Powders for Additive Manufacturing

The NiAl–Cr–Co–X alloys were produced by centrifugal self-propagating high-temperature synthesis (SHS) casting. The effects of dopants X = La, Mo, Zr, Ta, and Re on combustion, as well as the phase composition, structure, and properties of the resulting cast alloys, have been studied. The greatest improvement in overall properties was achieved when the alloys were co-doped with 15% Mo and 1.5% Re. By forming a ductile matrix, molybdenum enhanced strength characteristics up to the values σucs = 1604 ± 80 MPa, σys = 1520 ± 80 MPa, and εpd = 0.79%, while annealing at T = 1250 ℃ and t = 180 min improved strength characteristics to the following level: σucs = 1800 ± 80 MPa, σys = 1670 ± 80 MPa, and εpd = 1.58%. Rhenium modified the structure of the alloy and further improved its properties. The mechanical properties of the NiAl, ZrNi5, Ni0.92Ta0.08, (Al,Ta)Ni3, and Al(Re,Ni)3 phases were determined by nanoindentation. The three-level hierarchical structure of the NiAl–Cr–Co+15%Mo alloy was identified. The optimal plasma treatment regime was identified, and narrow-fraction powders (fraction 8–27 µm) characterized by 95% degree of spheroidization and the content of nanosized fraction <5% were obtained.

EVALUATION OF THE POSSIBILITY OF THE PRODUCTION A SOLVENT WITH A LOW CONTENT OF AROMATIC HYDROCARBONS IN JSC «ANHK»

. In connection with the emerging demand for gasoline solvent with a low content of aromatic hydrocarbons we carrier out the analysis of intermediate products obtained in JSC " ANHK " suitable for the producing of the solvent. The most suitable for the separation of the fraction are gaso line fractions producing from the hydrogenation product of the hydrocracking of light vacuum gas oil and the hydrogenation product of high conversion hydrogenation of the heavy middle distillate frac tions. We performed work on the recovery of a narrow fraction of gasoline solvent and its tests for compliance with the requirements.

Crush and Acid Resistance of Microsphere Narrow Fractions from Fly Ash as the Basis of Composite Materials

The crush test and acid resistance of microsphere narrow fractions with average diameter dav of 5, 8 and 25 μm of the SiO2–Al2O3–FeO system and with dav of 4 and 10 μm the CaO–SiO2–Al2O3– FeO system separated from fly ash from pulverized combustion of Ekibastuz and Irsha-Borodinsky coals were studied. It has been established that all investigated ash fractions of both raw materials are characterized by high strength: microspheres of a larger narrow fraction with dav = 25 μ m a re not destroyed by compressive loading at pressures up to 51.7 MPa, dispersed narrow fractions of microspheres with dav ≤ 10 μm – up to 68.9 MPa. Microsphere narrow fractions with aluminosilicate composition have satisfactory acid resistance; the weight loss after treatment with 15 % hydrochloric acid at 65 °C for 30 minutes was 10–15 wt. %

Study of the influence of synthesis technologies on the properties of syntactic carbon foams

The paper studied the influence of starting components and operating conditions of synthesis processes on the performance properties of syntactic carbon foams. The studies determined the behavior and ranges of hardness, ultimate compressive strength, apparent density, and thermal conductivity of foams made by template carbonization and using carbon microballoons, depending on heat treatment temperature. They determined the influence of a volatile blowing agent (sodium chloride) with wide and narrow fraction on a change in the studied properties of syntactic carbon foams.

Metallographic Study of Mesostructure-Ordered Plasma Ceramic Coatings

This article provides the reader with results of the study of mesostructure ordered plasma ceramic coatings derived from narrow-fraction powders under optimum modes for this fraction. It is noted that it is succeeded to implement mesostructure ordering of coatings eliminating the formation of continuous columnar structures by means of spraying mode control. It is proven that it is possible to get formation of nanocolumnar structures in a near surface layer, and these structures provide bonds damping between clusters under alternating force and thermal loads of coated parts. To evaluate the quality of formed ordered structure, a quantitative criterion—mesostructure ordering coefficient—is used. The Methods of quantitative evaluation of mesoordering of coating structure has been developed.