Titan №3 2021

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Materials science

 

INFLUENCE OF Fe, Ni AND Cr IMPURITIES ON THE COMPLEX OF MECHANICAL PROPERTIES OF THE VT18U ALLOY

 

M.O. Leder, E.N. Kondrashov, K.A. Rusakov, M.V. Kostyaeva, A.A. Popov

 

The paper focuses on the influence of changes in the chemical composition on the mechanical properties of VT18U-type alloy. Variations of the main alloying elements, as well as Fe, Ni and Cr impurities are considered. The integral characteristics of mechanical properties are presented for the first time. It is shown that a decrease in the content of Fe, Ni and Cr impurities significantly affects the creep and stress rupture properties of the alloy, and an increase in the ratio Si/[Fe] leads to an increase in the toughness properties such as KCU and KCT.

 

Keywords: near-alpha titanium alloys, VT18U, mechanical properties, impurities, fast diffusing elements.

 

INVESTIGATION OF THE POSSIBILITY OF REPLACING CASTING OF TITANIUM ALLOYS WITH 3D PRINTING TECHNOLOGY

 

V.P. Leonov, N.F. Molchanova, E.V. Chudakov, M.V. Iksanov

 

Direct laser deposition is promising for the manufacture of large-sized semifinished of complex shape instead of castings. To determine the eligibility of this replacement, it is necessary to conduct research on the compliance of the mechanical and service properties of the metal obtained by direct laser deposition with the requirements for cast metal. The article presents the results of preliminary studies of the structure and standard mechanical properties of the metal of the deposited parts from the powder of the titanium alloy (TL5) and their comparative analysis with the cast metal.

 

Keywords: titanium alloy, direct laser deposition, castings, powder material, mechanical properties, structure.

 

THE CLASSIFICATION OF TITANIUM ALLOYS WITH RESPECT TO THEIR OPERATIONAL RELIABILITY

 

S.V. Serikov

 

A method for the classification of titanium alloys with respect to their operational reliability is proposed. A new concept is introduced - the metal genome, which contains seven parameters (σb, σ02, δ5, μ, А*, έ, T). Their definition is concretized in the article. Examples of the efficiency of the method on titanium alloys are given. A significant dependence of the operational reliability of alloys on their chemical composition, heat treatment and preliminary plastic deformation is shown.

 

Keywords: titanium alloys, metal genome, coefficient of dynamic viscosity, specific work of destruction, crack resistance of deformation.

 

POSSIBLE RANGE OF CHANGING THE PROPERTIES OF HOT ROLLED BARS FROM TITANIUM–ALUMINUM–NIOBIUM ALLOY

 

Y.N. Loginov, F.V. Vodolazskii, D.D. Toyusheva

 

Statistical processing of the array of mechanical properties of rods made of Ti6Al7Nb alloy, rolled to various diameters in the range of 7 ... 65 mm, has been carried out. Calculations of the values of the elongation coefficient, relative reduction, accumulated during rolling are performed. The entire data array is divided into ranges. For each range, the average values of mechanical properties were calculated and histograms of their distribution over the averaged diameters were plotted. Analysis of variance is also cited. At the same time, it is shown that the indicator of the ratio of the yield strength to the ultimate strength tends to decrease as additional plastic deformation is reported.

 

Keywords: titanium alloys, hot rolling, mechanical properties, statistical processing

 

VARIOUS METHODS FEATURES OF TITANIUM ALLOYS RUTHENIUM MODIFICATION TO IMPROVE CORROSIONS RESISTANCE

 

V.P. Leonov, E.V. Chudakov, Yu.Yu. Malinkina

 

Various methods of titanium alloys ruthenium modification of the systems Ti-Al-Zr + 0.15% Ru, Ti-Al-V-Mo + 0.15% Ru and similar systems of basic compositions are considered.

Based on the performed studies set the localized content and ruthenium distribution in the structure were analyzed. As result, the most suitable corrosion resistance methods of protection were selected.

 

Keywords: modified titanium alloys, ruthenium, forgings, corrosion resistance, coatings, microalloying.

Processing technologies

FORMATION OF THE STRUCTURE AND MECHANICAL PROPERTIES OF HIGH-ALLOY TITANIUM ALLOYS DURING ISOTHERMAL FORGING IN AIR

A.V. Skugorev, D.V. Kapitanenko, S.Yu. Shishkov, D.A. Mel’nikova

This paper studies the features of the formation of the structure and mechanical properties during isothermal forging and subsequent heat treatment of high-alloy titanium alloys VT22 and VT23. The optimal temperature and speed parameters of isothermal deformation of high-alloy titanium alloys with different types of the original structure have been determined. Process parameters of isothermal deformation of VT22 and VT23 alloys, which provide a high complex of mechanical properties of the deformed semi-finished products after hardening heat treatment, were proposed.

Keywords: high-alloy titanium alloys, isothermal forging, thermomechanical treatment, structure, mechanical properties.

LOW TEMPERATURE ION NITRIDING OF THE Ti-6Al-4V TITANIUM ALLOY IN A GLOW DISCHARGE AND IN A NON-SELF-SUSTAINED HIGH-CURRENT ARC DISCHARGE

A.F. Tagirov, R.D. Agzamov, A.A. Nikolaev

 

The results of two series of experiments on the process of low-temperature ion nitriding of the Ti-6Al-4V titanium alloy in a non-self-sustained high-current arc discharge and in a glow discharge are presented. The results of X-ray phase research, microhardness along the depth of the modified layer, roughness, residual stresses in the surface layer of the samples are presented. The results of fatigue tests of blades after low-temperature ion nitriding are presented.

 

Keywords: titanium alloy, ion nitriding, roughness, microhardness, residual stresses, fatigue strength.

 

 

Application. Quality. Market

 

COMPOSITE METAL - POLYMERIC MATERIALS WITH SHAPE MEMORY EFFECT AND SUPERELASTICITY FOR MEDICAL DEVICES

 

D.E. Gusev, R.E. Vinogradov, M.Yu. Kollerov, E.A. Lukina, A.A. Chernyshova

 

A comparison of the thermomechanical properties of various composite materials with a polymer matrix (silicone rubber, polyethylene, carbon fiber) reinforced NiTi wire was made. The basic principles of choosing the matrix and reinforcing elements to ensure the required functional properties (superelasticity and shape memory effect) of composites were formulated. The prospects of using functional metal-polymer composites for the manufacture of orthopedic products were shown.

 

Keywords: NiTi, titanium nickelide, composite material, silicone rubber, polyethylene, carbon fiber, mechanical testing, shape memory effect, superelasticity.