№2 2017
Materials science
Physico-technological properties of composite material based on powder of titanium alloy VT22
O. Romanova, O. Rybalko, B. Gelchinskiy, M. Zakharov, A. Dolmatov, D. Kryuchkov
The research of the new composite material received on the basis of powder alloy of VT22 (60%) and powders of titanium PTM-1 (10%) and nickel PNK-UT3 (30%) is conducted. Mechanical properties of sintered material, phase composition and microstructure are studied. It is shown that the high hardness (HB) of the received material is explained by formation of an intermetallid of NiTi at agglomeration, and the increased fragility is connected with heterogeneity and high porosity of a compact.
Keywords: titanium alloys, powder, pressing, sintering, compressive strength.

Twins in SLM Ti-6Al-4V alloys
N. Kazantseva, P. Krakhmalev, G. Fredriksson, N. Vinogradova, I. Yadroitsev, I. Ezhov
Twinning process in medical Ti-6Al-4V titanium alloys obtained by selective laser melting (SLM) was investigated. {10 2}< 011> Twinning system in the alloys after SLM and additional annealing at 650C was identified. Comparison of twins among conventional, HIP, and SLM titanium alloys is provided.
Keywords: additive technologies, Ti-6Al-4V, twinning, TEM.

Compression testing of porous implant manufactured of titanium alloy by means of additive technology
Yu. Loginov, A. Popov, S. Stepanov, E. Kovalev
Compression testing data on porous implant of titanium alloy was analyzed according to the international standard ISO 13314. Typical points were revealed and corresponding characteristics were calculated for the stress-strain curve as stated in standard. Relation between stresses occurring upon loading and forming of pore walls, cells was investigated based on video registration of deformation and loading parameters. Nonmonotonicity and inghomogeneity of cells forming were found and factors explaining them were formulated.
Keywords: titanium alloy, implant, inhomogeneous deformation, cellular porous structure, compression test.

Research on structure and mechanical properties of wrought intermetallic titanium based alloy VIT5 doped with gadolinium
N. Nochovnaya, E. Alexeev, P. Panin, A. Novak
There have been shown studies results of the wrought Ti2AlNb-phase based alloy marked VIT5. It has been shown that microaddings gadolinium doping increases the strength and heat resistant characteristics of the material and provides a fine-grain structure after as melting, so as the deformation and thermal treatments. The work is done within the framework of the complex scientific direction 7.1 “Intermetallic titanium based alloys” (“Strategic Directions of Materials Development and Their Processing Technologies for the Period up to 2030”).
Keywords: high-temperature titanium alloys, intermetallics, ortho alloys, vacuum-arc melting, ingot, heat treatment, chemical composition, phase composition, structure, mechanical properties.

Improving stability of mechanical properties of deformed semi-finished products from titanium alloy Ti-6Al-4V
J. Egorova, Davidenko, E. Chibisova, I. Mamonov, S. Belova
The statistical dependences of mechanical properties on the chemical composition of bars and forgings from various modifications of Ti-6Al-4V alloy after heat treatment were investigated. The part of the variation in mechanical properties due to the variations in the content of alloying elements and admixtures is estimated. Recommendations for adjusting the chemical composition for improving the stability of properties have been developed.
Keywords: titanium alloys, ingots, deformed semi-finished products, chemical composition, mechanical properties, statistical research.

Influence of a phases volume ratio on deformation behavior of titanium alloys
A. Ovchinnikov
Influence of a hydrogen alloying on quantitative phase structure and flow stress of the commercial pure titanium and Ti-6Al alloys is investigated. Based on the analysis of the received results structurally compensated rule of mixes describing deformation behavior of alloys in two-phase α+β- areas is offered.
Keywords: titanium, deformation, hydrogen, structure, flow stress.

Computer modeling of process of a hydrogenation of a surface layer of cylindrical billet of vt6 titanium alloy
A. Dranicin
To improve workability cutting of billets from titanium alloys within an allowance for machining it is rational to apply a hydrogenation of a surface layer of billets. The mathematical model of process of a hydrogenation of a surface layer of cylindrical billet with diameter of 48 mm of VT6 alloy is given in article. Computer modeling based on model showed a satisfactory consent of calculated distribution of concentration of hydrogen in billet with experimental data.
Keywords: hydrogenation of surface layer of billet, Siverts’s equipment, mathematical model, computer modeling, distribution of concentration of hydrogen, titanium alloys.

Events and anniversaries
MAI Stupino affiliated branch department «Technology and automation of materials processing» – 50 years
To the 65-year anniversary Alexander Ilyin
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