Titan №3 2016
Raw materials. Titanium sponge
ACTUAL, POTENTIAL AND PROSPECTIVE SOURCES OF TITANIUM RAW MATERIALS
L. Bykhovsky, A. Lapshin, L. Sporykhina, O. Chebotareva
Russian Federation is one of the leading countries with significant titanium reserves. Currently the country is producing a wide array of titanium products from metal to titanium dioxide pigment. The processed raw material is mainly imported from foreign countries. The most important open question is determination of suitibility and development of sources of raw materials inland to except the whole import value. There are discussed some recommendations for deposits to priority development in this article, based on domestic industry demand in the short and mid-term.
Keywords: titanium reserves, sources of titanium raw materials.
INFLUENCE MICROALLOING INCLUDING REM ON THE STRUCTURE, PHASE COMPOSITION AND PROPERTIES OF (a + b) TITANIUM ALLOYS AT HARDENING HEAT TREATMENT
A. Illarionov, A. Popov, S. Illarionova
Alloy of martensitic class of system Ti-Al-Mo-V-Cr-Fe microalloyed by yttrium (alloy 1) and zirconium (alloy 2) after quenching of two-phase a + b- region for b-solid solution and subsequent aging was investigated. It is shown that in the alloys 1 and 2 in the aging temperature range 450-550°C decomposition of the metastable b-solid solution is dispersed to form a secondary a-particles. The increase of aging time delay contributes to more complete of decomposition, the lattice reduction period b-phase and predominantly by hardening of alloys. It is found that the alloy 1 with yttrium achievable level of performance in aging hardness higher than in alloy 2 with zirconium, resulting in a greater volume fraction in the alloy 1 of the metastable b-solid solution, which undergoes decomposition.
Keywords: (a+β) - titanium alloy, microalloying rare-earth metals, quenching, aging, the metastable β-solid solution, decay, hardness.
PHASE TRANSFORMATIONS IN METASTABLE b-SOLID SOLUTION DURING HEAT TREATMENT PSEUDO-b TITANIUM ALLOY WITH REM
S. Illarionova, O. Elkina, A. Illarionov
Pseudo-b alloy of system Ti-Al-V-Cr-Zr-Sn microalloyed by yttrium (alloy 1) and yttrium + germanium (alloy 2) after quenching of two-phase and b-phase region and the subsequent aging ranging 475‒525°С was studied. It was found the process of decomposition of metastable b-solid solution during aging is more active in b-quenched state. It is shown the increase of the aging temperature from 475 to 525°C reduces the rate of presipitation of secondary a-phase and the age hardening. It found that introduction of yttrium in the alloy leads to the formation of Y2O3 particles and germanium does not form additional phases, but may reduce the resistance b-phase to processes of decay.
Keywords: pseudo-b titanium alloy, microalloying rare-earth metals, quenching, aging, the metastable b-solid solution, decay, hardness.
RESEARCH OF INFLUENCE RUTHENIUM ON CORROSION PROPERTIES OF THE DEFORMED SEMI-FINISHED PRODUCTS FROM TITANIUM ALLOYS FOR PERSPECTIVE SEA EQUIPMENT
V. Leonov, E. Chudakov, L. Rtishcheva, Yu. Malinkina, P. Tryaev, A. Mikhaylov, D. Pryakhin
In work results of researches of two types of the deformed semi-finished products (bars and pipes) from titanium alloys of the Ti-Al-Zr and Ti-Al-Zr+0,15% Ru of system are considered.
The main mechanical properties, structure and distribution of ruthenium on structure of titanium alloys are presented. Results of tests on slot-hole and salt corrosion of bars and pipes from these alloys are also considered.
Recommendations about carrying out washings of samples after tests for corrosion are made.
Keywords: titanium alloys, ruthenium, slot-hole corrosion, salt corrosion, washings.
COMPARISON OF DEFORMABILITY OF PSEUDO b-TITANIUM ALLOYS AT ROOM TEMPERATURE
S. Skvortsova, I. Grushin, A. Volodin, S. Yudaev, A. Neiman
The chemical composition and the properties analysis of the near beta-titanium alloys has been performed. It has been demonstrated that VT35 and VT32 are the most advanced native alloys for the fixture elements fabrication. The comparative analysis of the technological plasticity has been carried out on the prototype samples of these alloys at room temperature. During the upsetting test it has been established that VT35 has the lower yield strength in comparison with VT32, which is to say that VT35 is more preferable for the fixture elements fabrication.
Keywords: near beta-titanium alloys, heat treatment, structure, phase composition, yield strength, fixture elements.
INVESTIGATION OF WEAR RESISTANCE OF MEDICAL GRADE TITANIUM NICKELIDE
E. Lukina, M. Kollerov, P. Panin, A. Khon
The influence of the material structure and lubrication conditions on the wear resistance of Nitinol intended for use as a rod in dynamic fusionless spinal constructs with titanium screws was experimentally studied. Lubrication conditions have a dramatic effect on the wear performance of Nitinol. When tested in diluted calf serum Nitinol demonstrated high wear resistance comparable to that of Co-Mo-Cr alloy. However, its performance deteriorated by up to 12 fold when tested in water without proteins and by up to 130 fold without lubrication.
Keywords: titanium nickelide, wear, medical implants, pedicle screw instrumentation.
Semi-products manufacturing technologies
SMELTING OF THE Al-V-Ti-C MASTER ALLOY BY DUPLEX PROCESS
S. Vohmentsev, A. Rylov, М. Trubachev, D. Taranov, V. Chumarev, A. Larionov
The possibility of the Al-V-Ti-C master alloy smelting by duplex process including aluminothermic reduction and vacuum induction melting was studied. Selection of equipment and smelting regimes was made. Substantiation of choice of crucible material was made. It was shown, that the Al-V-Ti-C master alloy obtained by duplex process satisfies the requirements for Al-V-Ti-C master alloy in chemical composition and surface condition.
Keywords: vanadium, aluminum, titanium, carbon, master alloy, vacuum induction melting.
Semi-products treatment technologies
NEW SHEET TITANIUM ALLOY VST2k FOR LOW-TEMPERATURE TECHNOLOGY OF SUPERPLASTIC FORMING AND DIFFUSION BONDING
R. Safiullin, R. Galeyev, M. Mukhametrakhimov, R. Hazgaliev, S. Malysheva, R. Mulyukov, A. Kozlov, A. Berestov, M. Leder
Investigations of technological properties of new titanium alloy sheet VST2k have been conducted. It is found that the titanium alloy has a good solid state weldability and formability under conditions of superplasticity at temperatures 750-900ºC. By the method of SPF/DB sheet of VST2k alloy in a low-temperature superplasticity at a temperature of 800ºC has successfully made hollow blade model. The obtained results allow to recommend VST2k titanium alloy to be used in SPF/DB technology, particularly at low temperatures.
Keywords: microstructure, superplasticity, titanium alloy, formability, diffusion bonding.