Ti4Al3V-Fe alloys have been obtained using wire and electron beam additive manufacturing that contained 1.7, 2.5 and 7.5 wt.% Fe. The first two alloys were composed of α/β lath structures, the third one was a fully β-Ti alloy reinforced by isothermal -Ti precipitates. Compression testing demonstrated TRIP behavior on the Ti4Al3V-7.5Fe alloys, which allowed achieving a combination of higher hardness with higher plasticity. This TRIP effect was due to β transformation under plastic deformation by dislocation slip. Such a combination of properties provided better wear resistance in rubbing against a steel counterpart. Layered Al2O3/TiO structures were observed in tribological layers of all sampl

The paper studies the layer degradation on the nozzle and electrode surface of plasma torches operating at a current with applied reverse polarity. AA5056 and AA2024 aluminum alloy sheets are used for plasma cutting. It is demonstrated that the surface of the nozzle channel and discharge chamber of the plasma torch are covered with the aluminum layer, that can be attributed to its evaporation in the cutting zone. Copper oxides and insignificant aluminum traces are observed on the surface of the discharge chamber and electrode channel. These copper oxides can almost completely block the water injection in the channel making it unusable.

The present study provides the first systematic investigation of Fe addition (1.7–7.5 wt

Defect-free thin-walled samples were built using wire arc additive manufacturing (WAAM) combined with the “coldArc” deposition technique by feeding a Ti-6Al-4V welding wire and using two deposition strategies, namely with and without the welding torch weaving. The microstructures formed in these samples were examined in relation to mechanical characteristics. The arc torch weaving at 1 Hz allowed us to interfere with the epitaxial growth of the β-Ti columnar grains and, thus, obtain them a lower aspect ratio. Upon cooling, the α/α′+β structure was formed inside the former β-Ti grains, and this structure proved to be more uniform as compared to that of the samples built without the weaving. The subtransus quenching of the samples in water did not have any effect on the structure and properties of samples built with the arc torch weaving, whereas a more uniform grain structure was formed in the sample built without weaving. Quenching resulted also in a reduction in the relative elongation by 30% in both cases.

The effect of heat treatment on the structural evolution, phase transformation, and mechanical strength of Al–12Si obtained using wire electron beam additive manufacturing has been investigated. The as-built Al–12Si alloy was characterized by structural inhomogeneities in the form of interlayer bands with coarsened Si particles resulted from cyclic reheating of the solidified metal. Quenching the as-built samples resulted in the increase of the volume fraction of Al/Si eutectics by 9

The structural-phase state and mechanical characteristics of the Ti6Al4V alloy added with 0.6, 1.6, 6 and 9.7 wt.% of copper, obtained using the double-wire electron beam additive manufacturing (EBAM) have been studied. It was found out that adding copper to the Ti6Al4V alloy resulted in the formation of equiaxed grains and precipitation of Ti2Cu particles that allowed improving both yield strength and tensile strength compared to those of the base EBAM Ti6Al4V. Contributions of three different strengthening mechanisms into yield strength of the Ti6Al4V-Cu alloys have been determined. It has been established that grain boundary strengthening provided main contribution to improving mechanical characteristics of Ti6Al4V-Cu alloys. The contributions of dispersion and solid solution hardening mechanisms to the improvement of the yield strength are comparable and smaller than that of the grain-boundary hardening.

Hypereutectoid Ti6Al4V–Cu alloys containing 15, 19 and 25 wt

The structural features and phase composition were examined in near-surface layers in samples of Al-Mg, Al-Cu-Mg alloys and commercially pure titanium obtained by plasma cutting using direct current straight polarity (DCSP) and direct current reverse polarity (DCRP). It was found that the flows of molten metal carried away by the gas stream from the cut cavity during cutting form molten and heat affected zones, whose structural morphology, phase composition and thickness depend on both the selected material and the cutting mode. The thickness of the molten zone is larger for samples cut using DCRP than for those cut with DCSP. The thickness of the adjacent heat affected zone is also the greatest under conditions that provide a large thickness of the fused layer. Aluminum alloy samples cut in ambient air are characterized by the presence of oxygen in the near-surface layers. The lowest degree of oxidation is observed in Al-Mg alloy. Oxygen penetrates into the fused layer to a depth of 350-500 μm in Al-Cu-Mg and up to 200-250 μm in Al-Mg alloy. In titanium alloy, the thickness of the oxide layers does not exceed 100-150 μm when cutting with DCSP and 200-250 μm when cutting with DCRP. A thin brittle layer of TiO and TiO2 oxides is formed on the titanium alloy surface. It was shown that the release of “water mist” around the plasma jet when cutting materials of all types with DCRP leads to more intense oxidation of metal, less thermal effect on the material, and reduced roughness of the cut surface.

Structural evolution, mechanical and tribological properties of Al-Mg alloy admixed with 5, 10 and 15 vol.% of iron powder using multi-pass friction stir processing (FSP) have been studied. Homogeneous distribution of intermetallic compound (IMC) particles were achieved after 4 FSP passes what resulted in increasing the stir zone hardness and ultimate tensile stress with simultaneous loss in the ductility. The reinforcement of the aluminum alloy matrix with IMCs allowed reducing wear at the same magnitude of friction. Subsurface composite tribological layer was formed on the FSPed samples as a result of rubbing against a steel counterbody.

Silicon bronze CuSi3Mn1 wall has been built using WAAM that demonstrated its dendritic microstructure composed of both columnar and equiaxed alpha-Cu grains as well as Mn5Si3 and MnFe2Si particles formed inside the interdendrite spaces. Hot cracks were formed in the regions enriched with the silicides that greatly affected the strength of samples with their tensile axis oriented along the wall's height (UTS 158 +/- 10 MPa) as compared to that oriented along the deposition direction (UTS 343 +/- 14 MPa).

The work is devoted to a review of modern achievements in the field of wire-feed electron beam additive manufacturing. The features of structure formation in aluminum, copper, titanium, nickel-based alloys, and steels during 3D printing are shown. Aspects of directional solidification during the production of components from various metals and alloys are considered. The prospects for obtaining composite and functionally graded materials based on various metals and alloys using wire-feed electron beam additive manufacturing are determined. The regularities of the structure modification and hardening of additively manufactured materials by the method of friction stir processing were considered. The main purpose of the review is to present additive manufacturing methods, the main focus being on the wire-feed electron beam additive manufacturing of metal alloys.

In the presented work, the effect of friction stir processing admixing the zirconium tungstate ZrW2O8 powder on the microstructure, mechanical and tribological properties of the AA5056 Al-Mg alloy stir zone has been studied. The FSP resulted in obtaining dense composite stir zones where α-ZrW2O8 underwent the following changes: (i) high-temperature transformation into metastable β’-ZrW2O8 and (ii) decomposition into WO3 and ZrO2 oxides followed by the formation of intermetallic compounds WAl12 and ZrAl3. These precipitates served as reinforcing phases to improve mechanical and tribological characteristics of the obtained fine-grained composites. The reduced values of wear rate and friction coefficient are due to the combined action the Hall–Petch mechanism and reinforcement by the decomposition products, including Al2O3, ZrO2, β’-ZrW2O8 and intermetallic compounds such as WAl12 and ZrAl3. Potential applications of the above-discussed composites maybe related to their improved tribological characteristics, for example in aerospace and vehicle-building industries.

The effects of heat input magnitude and adjustment on microstructure and mechanical characteristics of Al -5 %Si and Al-12 %Si alloys prepared using electron beam wire feed (EBAM) and wire -arc additive manufacturing (WAAM) have been investigated. The effect of aging under cyclic reheating the previously deposited layers has been revealed as depended on the heat input. The most prominent effect of Al -Fe -Si intermetallic particle coarsening was observed on Al -5 %Si after EBAM at maximum used heat input. Less heat input in case of EBAM on Al-12 %Si resulted in formation of aged eutectic banding structures which contributed to the anisotropy of their mechanical characteristics. The spheroidization and coarsening effect of WAAM Al -Si eutectics was less intensive as compared to that of EBAM since it related only to the Al -Fe -Si particle morphology.

Electron beam additive manufacturing with simultaneous feeding of two dissimilar metal wires was used to obtain Ti-6Al-4V specimens successively alloyed with 0.6, 1.6, 6.0 and 9.7 wt

Bacterial biofilms on titanium implant surfaces may lead to the development ofperi-implant diseases. For the first time, Ti6Al4V/Cu prepared by double-wire electron beam additive manufacturing (EBAM) were subjected to in -vitro antimicrobial test. The antimicrobial activity of the materials was investigated against S.aureus and C. albicans strains depending upon the amount of copper added. Increasing the copper content in material to 9.7 wt % allowed achieving 99% bacterial population reduction on the copper-containing substrate. Such an enhanced antimicrobial acivity of the substrate was caused by the release of copper ions from the Ti6Al4/Cu alloys.

The paper studies the influence of wire-arc additive manufacturing process parameters of aluminum– manganese bronze CuAl9Mn2 products on the structure and mechanical properties of samples The microstructure of aluminum bronze is defined by the presence of α-Cu(Al) solid solution and residual martensitic β-phase of Cu3Al. Insignificant anisotropy of mechanical properties of the samples cut in sections parallel and perpendicular to the direction of printing has been revealed. Samples cut in the cross section parallel to the printing direction show the highest values of the tensile strength and less ductility compared to the samples cut in cross section perpendicular to the printing direction. The tensile strength values vary from 515 MPa to 591 MPa between blades cut along and across the ply application. The strength of the hot-rolled product (440 MPa) is 25

The results of a study of the surface morphology and structural features of near-surface layers of titanium alloy samples of Grade2 and Ti-2Al-1.5Mn during plasma cutting are presented. The study reveals the formation of martensitic structures with a hardness considerably exceeding that of the base metal in the near-surface volumes of the samples. The Ti-2Al-1.5Mn alloy samples are characterized by relatively low surface oxidation, while the samples of Grade2 alloy are characterized by the formation of oxide layers with a hardness of up to 10–17 GPa. The cut zone structure depends largely on the cutting current and the corresponding values of the heat input. The bottom part of the cut is much less homogeneous than the top part, especially in the cases where the samples are stacked. Cutting with an initially insufficient heat input leads to the formation of beading in the bottom part of the samples or to significant disturbances in the macrogeometry of the cut.

The influence of a plasma jet on pure copper surfaces of different thicknesses is discussed. It is shown that during cutting, due to an intensive removal of molten metal from the cutting zone, a heat affected zone of large thickness and a fusion zone are mainly formed. Plasma cutting of copper sheets, especially those of large thicknesses, is complicated by the dynamic processes of melting, flow and crystallization of the metal displaced from the cavity cut by the gas jet. Inhomogeneities in the metal flow from the cutting zone, a high rate of heat removal and crystallization cause the formation of beading in the lower part of the cut, and its size increases significantly with the thickness of the cut parts.