Raw materials. Metallurgy
A new approach to the development of the torchin residual deposit of apatite-ilmenite ores (Ukrainian shield)
T.V. Okholina, O.O. Remezova, U.Z. Naumenko, S.P. Vasylenko, H.A. Kuzmanenko,
O.V. Yaremenko, O.L. Aleksandrov
The prospects of the development of the Torchin residual apatite-ilmenite ore deposit have been discussed in the article. Based on computer modeling, the authors proposed to develop the Torchin deposit in small blocks, which will ensure high work productivity, minimal impact on the environment and will allow replenishing the mineral and raw material base of the titanium industry in Ukraine at the expense of new type deposits.
Keywords: Ukraine, Torchin deposit, ilmenite, Ukrainian shield, development
Investigation of the structure and properties of titanium alloy VT6, produced using technology of direct laser deposition with subsequent heat treatment
O.G. Klimova-Korsmik, M.O. Gushchina, S.A. Shalnova, P.A. Golovin
Additive technology of direct laser deposition is prospective for producing large scale complexity parts and construction. Using of the DLD allows significantly reduce cost and decrease producing cycle numbers as well as get a bionic product design. At the moment, it is necessary to thoroughly test the parameters of the mode of the process of direct laser deposition. This paper is devoted to the study of the structure and properties, as well as the effect of post-processing on the quality of deposited products.
Keywords: direct laser deposition, additive technologies, titanium alloys, heat-treatment.
Influence of the microstructure on mechanical properties of VT25U heat resistant titanium alloy
Pavlova T.V., Kashapov O.S., Kalashnikov V.S., Goncharova L.Y.
The article presents the experimental results of two-phase heat-resistant titanium alloy VT25U forgings study. During the study, five experimental forgings were manufactured using various technological schemes. The technological schemes were chosen in respect to obtain a material with a fine grain and lamellar structures with a different morphology of α-phase and microstructure parameters. The characteristics of strength and creep strength (time to rapture), impact toughness, and high-cycle fatigue of smooth and notched samples (at room temperature) are determined. It is demonstrated that the improvement of b-deformation technology is a very promising direction of research. It is possible to achieve high heat resistance and fatigue strength of the material in relatively large industrial forgings with a certain morphology of lamellar structure and it is especially important for the high-pressure blisks of gas turbine engines.
Keywords: high cycle fatigue, mechanical properties, titanium alloys, forging, heat treatment.
Linear gradient structure creation in VT6 titanium alloy
S.V. Skvortsova, O.N. Gvozdeva, A.V. Shalin, A.S. Stepushin
In this work, the influence of the heating temperature in an air atmosphere on the pattern of oxide films formation in VT6 titanium alloy was shown. The behavior of the oxide and alpha-coated layers during the subsequent processing in vacuum was studied. It has been established that preliminary heat treatment must be applied at temperatures above 800°C to protect the semi-finished product from the penetration of hydrogen during thermohydrogen treatment. Oxide films usage to insulate the selected sides of semi-finished product during «linear» gradient structure creation was investigated.
Keywords: titanium alloy, oxide film, alpha-coated layer, microhardness, thickness, hydrating annealing, gradient structure, martensite.
Information technologies in metal science of titanium alloys: problems, opportunities and prospects
Yu.B. Egorova, I.M. Mamonov, L.V. Davidenko, E.V. Chibisova, A.V. Chelpanov
The questions of development of information technologies in the field of metal science of titanium alloys are considered. The review of information systems, databases and packages for alloy modeling and prediction of their properties is carried out. The concept of creation of the multiuser system intended for collecting, storage in open access and processing of data on titanium alloys, forecasting of properties of semi-finished products and discussion of results is offered.
Keywords: titanium alloys, information systems, databases, modeling of alloys, prediction of properties.
The influence of the metallurgical and technological defects on the titanium parts of the power equipment strength
V.V. Travin, A.I. Zmozhniy, G.A. Shevelev
The problems of the strength providing for the titanium parts containing the defects are described. The results of the strength numerical investigation for the plates and shells containing the three dimensional defect are represented. Also the example of the durability estimation of the steam drive wheel with the crack inside weld is given. Using of the finite element method allows to approximate the models to the actual work conditions and to justify whether the mending or the using or the rejecting of the defective part.
Keywords: defect, titanium alloys, strength, pore, damage factor.
Prospects of application of β-deformation for high-strength titanium alloy of transition class VT22M
V.A. Krokhinа, S.V. Putyrskiy, A.L. Yakovlev, N.A. Nochovnayа
The aim of this report is the study of mechanical properties, such as tensile properties and fracture toughness, for two die forgings of same shape, which made with final deformation in α+β and β temperature range. Results of microstructure study and there correlation with mechanical properties are presented too. On the foundation of presented results the directions of future investigations in the area of choosing β-heat treatment parameters and mechanical properties study are defined.
Keywords: high-strength titanium alloys, deformation, mechanical properties, microstructure, fracture toughness.
Events and anniversaries
For the anniversary of Nadezhda Nochovnaya
To the 60-year anniversary Alexandr Grishechkin