Materials Science

 

DEPENDENCE OF MECHANICAL PROPERTIES AND DYNAMIC STABILITY OF A PILOT METASTABLE β-TITANIUM ALLOY ON STRUCTURAL-PHASE COMPOSITION AND HEAT TREATMENT MODES

 

A.A. Ilyin, E.A. Kuryishev, N.A. Nochovnaya, A.A. Shirayev, A.S. Stepushin

 

Up-to-date information is introduced concerning correlations between mechanical properties and dynamic strength of titanium alloys of various classes in dependence on structure and phase composition thereof. A research on effect of technological parameters of aging on both mechanical properties and dynamic strength of sheet semi-finished products from a pilot high-strength metastable β-titanium alloy has been accomplished. The heat treatment conditions for the formation of zones in the alloy structure which are free or depleted of precipitates, and their behavior effect on mechanical properties and dynamic strength have been determined.

 

Keywords: metastable β-titanium alloys, high strength titanium alloys, precipitate-free zone (PFZ), microstructure, mechanical properties.

 

ON THE APPLICATION OF EQUIVALENTS OF ALLOYING ELEMENTS AND IMPURITIES TO ALUMINUM AND MOLYBDENUM IN TITANIUM ALLOYS PRODUCTION

 

A.A. Il’in, I.S. Polkin, Yu. B. Egorova, L.V. Davidenko

 

On the basis of statistical generalization of the accumulated experimental and industrial data as well as theoretical research in the field of metallurgy and heat treatment of titanium alloys, the principles of mapping the chemical composition and mechanical properties of titanium alloys were considered. The ability to assess the complex properties and improving the quality of semi-finished products using structural and strength equivalents of alloying elements to molybdenum and aluminum were investigated.

 

Keywords: titanium alloys, mechanical properties, structural strength and equivalents for aluminum and molybdenum, forecasting, quality products.

 

RESEARCH OF HEAT TREATMENT PARAMETERS EFFECT ON STRUCTURE AND PROPERTIES OF (a+b) TITANIUM ALLOYS

 

S.V. Skvortsova, O.N. Gvozdeva, N.V. Ruchina, A.E. Ivanov

 

This work presents results in research of the effect of heating temperature and cooling rate on phase composition, structure, technological and mechanical properties of a rod stock made of the VT16 two-phase (a+b) titanium alloy. It is stated that cooling rate does not substantially affect structure formation after annealing at the temperatures of 680° and 700°C and provides ultimate compression degree under upsetting on the level of 75%. It is shown that the same level is obtained after heating up to 750°C and following furnace cooling. It is also stated that the maximum technological plasticity of more than 78% can be achieved after a two-step annealing. This work shows that obtaining required values of strength, elongation and contraction, and shear stress is possible by means of strengthening heat treatment at the temperature of 450°C.

 

Keywords: (a+b)-titanium alloys, cooling rate, heating temperature, heat treatment, upsetting, ultimate strength, shear stress, fastening parts.

 

RESEARCH OF LARGE-SCALE FACTOR INFLUENCE ON STATIC AND RESOURCE CHARACTERISTICS UPON TESTS OF ELEMENTARY SAMPLES MADE OF VT23 AND VT23M ALLOYS

 

Yu.A. Popova, A.A. Filatov, A.A. Akulinin

 

Influence of a large-scale factor of the tested samples is investigated to confirm mechanical properties by example of high-strength VT23 and VT23M titanium alloys. Results of static tension and crack growth resistance tests of welded and not welded samples of various semi-finished products are given and analyzed. There are drawn conclusions on influence of the overall dimensions of the samples on the obtained characteristics.

 

Keywords: titanium alloy, large-scale factor, mechanical properties, samples for mechanical tests, fatigue crack growth analysis.

 

 

Manufacturing technologies

 

ADDITIVE TECHNOLOGIES IN TITANIUM MANUFACTURE

 

А.V. Dub, Y.N. Loginov, A.A. Popov, S.V. Belikov, S.I. Stepanov

 

The principles of additive technologies are explained. The statistics of research and patenting by year and country is given. Commercial application is listed. The development of structure of titanium and its alloys are explained on the example of selective laser melting. Examples of technical implementation and evaluation of product quality are given. The necessity of special methods for quality estimation is demonstrated.

 

Keywords: additive technologies, titanium, selective laser melting, 3D printing, structure, properties.

 

RESULTS OF DEVELOPMENT AND PRODUCTION MASTERING OF PIPES MADE OF TITANIUM ALLOYS IN JSC CHMP

 

D.A. Negodin, D.O. Hlobystov, A.E. Moskalev, I.A. Dubovizkaya, L.P. Rtischeva, K.G. Martynov

 

Results of works of Research Center «Kurchatov Institute» – Central Research Institute KM «Prometey» and JSC «Chepetsk Mechanical Plant» on development of release of pipes made of titanium alloys for the atomic and ship-building industry are considered. Import substitution of the pipe production delivered earlier from Ukraine is as a result carried out. Pipes with a diameter from 3 to 325 mm are mastered and are delivered on the enterprises of the Russian Federation. Results of development of manufacturing techniques of pipes on foreign standards are given.

 

Keywords: titanium alloys, pipes, production, results of tests, especially thin-walled pipes, capillary pipes, pipes of big diameter.

 

 

Processing technologies

 

REGULARITIES OF STRUCTURE AND TEXTURE FORMATION UPON MANUFACTURING BARS OF (α+β) TITANIUM ALLOY AND THEIR INFLUENCE ON MECHANICAL PROPERTIES COMPLEX

 

S.V. Skvortsova, O.N. Gvozdeva, V.A. Lugovskoy, A.A. Shalin, I.A. Grushin

 

This work presents results of studies on the influence of deformation temperature on structure and texture formation in bars of a two-phase VT16 (α+β) titanium alloy. Optimal mode for combined thermomechanical and heat treatments of the bars is defined to form favorable crystallographic texture providing ultimate compression rate upon upsetting not less than 75% in rolling direction, and ultimate strength of 900 MPa and shear stress not less than 640 MPa in cross direction.

 

Keywords: (a+b) titanium alloys, structure, texture, deformation direction, heat treatment, upsetting, ultimate tensile strength, shear stress, fastener part.

 

 

Application. Quality. Market

 

PROPERTIES LEVEL OF TITANIUM IMPLANTS OBTAINED BY ADDITIVE TECHNOLOGIES

 

Y.N. Loginov, S.I. Stepanov, S.V. Belikov

 

The biocompatibility and osseointegration potential is noted in the application of titanium implants in medicine. Attention is drawn to the possibility of additive manufacturing in the production of implants. The achieved level of properties obtained by using additive technologies is not lower than that observed for traditional technologies. The results of mechanical testing are provided. The role of numeric simulation in architectural solutions for implants is noted. The simulation results are given. The importance of interaction with practical medicine is demonstrated.

 

Keywords: titanium, implants, additive manufacturing, numeric simulation, finite element method.