Papers by Keyword: Wire

Abstract: Excellent properties of titanium alloys as the high strength-to-weight ratio and exceptional corrosion resistance result very attractive for the industry. However, the high manufacturing costs of conventional processing methods, as well as the material waste remain challenging making these alloys only accessible to sectors such as aerospace.Additive manufacturing (AM) becomes an attractive solution to manufacture titanium based high-added value components due to the rapid prototyping, complex geometries manufacturing and waste reduction. Specifically, Laser Beam Directed Energy Deposition based on Metal Wire (DED-LB/Mw) process is becoming a key manufacturing process, mainly due to higher deposition rate, ability to build larger structures and high material efficiency compared with other usual AM technologies, as powder bed fusion (PBF), or powder-based DED processes (DED-LB/Mp). However, there are some challenges to industrialise the AM printed titanium alloys due to their high reactivity with oxygen at high temperature and mechanical properties of the deposited material because of extremely high residual stresses (RRSS).This paper reports the work carried out to demonstrate the feasibility of coaxial DED-LB/Mw process to manufacture a semi-spherical part, with potential application in the aerospace sector as a fuel tank. The work has been focused in three key issues:The effect of the argon shielding environments has been evaluated on three different configurations (local, inert chamber, local + inert chamber) to bring a deep understanding on the influence of protective conditions on process stability, surface quality, metallurgy and microhardness.The DED-LB/Mw processing of Ti-6Al-4V alloy has been parametrized to achieve the optimum process parameters attending to deposition rate and process stability. Mechanical properties have been also assessed on samples manufactured under the acceptable atmosphere condition.The optimal manufacturing strategy, with the established process parameters and protective atmosphere conditions, has been selected to manufacture the semi-spherical part also considering the trajectory limitations imposed by the required working movement conditions within the chamber

Abstract: Within the technologies that make up Additive Manufacturing (AM), one of the ones that have taken the greatest prominence in recent times is DED (Direct Energy Deposition), particularly that of wire feedstock. The W-DED/LB technique has some benefits compared to other AM methods, such as the fabrication of relatively larger parts, repair capabilities of the damaged areas of a component, cladding of different materials on existing parts, and reduced material waste.This study describes the optimisation of processing parameters for the manufacturing stainless steel (SS316L) and Inconel 718 alloys (INC718) using W-DED/LB. This is performed by modifying processing aspects like deposition trajectories, laser power, displacement speeds of the DED head, etc, with the aim of obtaining high deposition rates and a density above 99.5%. Once the alloy systems are optimised, a characterisation campaign has been performed, which includes a series of tests as well for defectology analysis using X-ray Computed Tomography (CT). Finally, the influence of different heat treatments on the tensile behaviour is analysed.This work has developed the technology of DED assembling in a Kuka-robot, so the challenge has not only been to control the DED system, but also the communication with the robotic arm to guarantee perfect harmony between all the parts that make up the W-DED/LB system.

Abstract: A twin-wheel caster with a hole nozzle was developed to cast thin aluminum alloy wire. The lower large wheel had a trapezoid groove with a cross-sectional area of 22.5 mm², and the upper small wheel was flat. Molten-metal flow onto the wheel was controlled by the gap between the wheel and the nozzle, and the ejection angle of the molten metal. When the gap was not appropriate, bulges formed on the free solidified surface of the molten metal on the wheel. The bulges were flattened by setting the gap to the correct size of 3 to 4 mm. The appropriate angle was found to be 60°. A thin wire of 6061 aluminum alloy could be cast continuously at a speed of 5 m/min. The cross-sectional area of the nozzle hole was 3 mm². The cross-sectional area of the as-cast wire was 42.7 mm².

Abstract: Shape memory alloys (SMAs) are promising materials for the creation of heating or cooling systems due to their elastocaloric character. The paper proposes a concept of elastocaloric “porous” SMA beam working in bending. The beam was made with superelastic nickel-titanium SMA wires of different diameters placed in a flexible tube. While water was flowing through the tube, bending was manually applied using 3D printed wavy profiles with portions of arcs with constant curvatures. Preliminary results showed an oscillation of the fluid temperature at the outlet of the flexible tube (containing the SMA wires) at the same frequency as the mechanical loading, validating therefore the concept of elastocaloric porous SMA beam operating in bending.

Abstract: This paper presents constructions of roller dies have been proposed, which make it possible to produce wire of simple and shaped profiles with a diameter of 0.5 to 12.0 mm. Technological solutions for the production of a hex profile S = 2.2 mm from a billet of hard-to-form alloys AISI 316, AISI 304, Ti3Al5Mo5V of various diameters are shown. To increase the service life of the dies, the rollers made of heat-treated steel of the X162CrMoV12 grade are recommended to be strengthened by applying a functional coating made of WC-10Co-4Cr alloy on the working surface by detonation sputtering followed by melting of this layer with a laser. Studies carried out on the samples showed a sevenfold increase in wear resistance in comparison with similar ones subjected only to the traditional for X162CrMoV12 heat treatment in the form of quenching and tempering.

Abstract: This paper presents the results of a study of changes in mechanical properties, namely tensile strength, yield strength and elongation when drawing a wire from NP2 nickel (Ni 99.6). The wire samples taken along the drawing route were tested for tension. Based on the test results obtained, graphs of changes in tensile strength, yield strength and elongation were plotted depending on cold work. The approximation of the graphs made it possible to obtain equations for the change in tensile strength (UTS), yield strength (0.2 US) and elongation (δ) depending on cold work (ɛ∑). The obtained dependences are recommended to be used to predict the mechanical properties of nickel wire during drawing and when developing software for designing resource-saving drawing routes.

Abstract: Coarse columnar dendrite greatly reduced the mechanical performance of GH3039 nickel-based alloy in the additive manufactured parts, which limited its application in the engineering fields. This study provides a comparison of overgrowth behaviors at diverging grain boundaries through two-dimensional phase field simulation, and the effect of dendrite orientation on overgrowth behavior was analyzed. Moreover, our results show that the primary spacing becomes larger as the increasing of dendrite orientation. The columnar dendrites branch new dendrites near grain boundaries to refine the primary arm spacing in the process of wire and laser additive manufacturing (WLAM).

Abstract: The paper presents the data obtained in the course of experimental studies on the production of rods from the Al-0.5% REM alloy using combined processing methods, such as combined rolling-extruding (CRE) and combined casting and rolling-extruding (CCRE). The variable parameters were the temperature of the ingot or melt, the degree of deformation and the strain rate. With the help of strain gauge equipment, experimental data were obtained on the forces acting on the rolls and the die of the CCRE-200 combined processing unit in the process of obtaining rods with a diameter of 5 and 9 mm. The estimation of the dependence of the mechanical properties of the rods on the variable factors has been carried out. The highest strength properties are possessed by a bar obtained by the CRE mode at a temperature T = 550 oC and a strain rate ξ = 0.74 s^-1. When comparing the temperature of pouring the metal, the highest strength properties are possessed by a rod with a diameter of 9 mm and 5 mm and a strain rate ξ = 0.74 s^-1. If compare in terms of the deformation rate, then the highest strength properties are possessed by a rod with a diameter of 5 mm and a deformation rate ξ = 1.49 s^-1. The plasticity of deformed semi-finished products in all modes is at a high level, which allows further processing.

Abstract: Analytical and experimental studies have been carried out, which made it possible to propose new technological modes of combined rolling-extruding for the production of rods from alloy 01417 for the further drawing of wire for electrical purposes. The force parameters on the rolls and the die are calculated when extruding a rod with a diameter of 5 mm on the laboratory unit CRE-200 and the industrial unit CRE-400. The obtained values of the forces on the rolls and the die do not exceed the permissible values of the power load of the units. Therefore the selected parameters are suitable for conducting experiments on the manufacture of prototypes of rods. To verify the conclusions made, experimental studies were carried out on the CRE-200 unit at a temperature of 320 oC and a drawing coefficient μ = 12.1. The results of experimental studies in comparison with the calculated data showed that the deviation of the calculated data does not exceed 15%.

Abstract: One of the possibilities of the dieless drawing is the production of ultrafine wire. In this case, it is possible for additionally stretch the wire, obtained in the conventional way. This may allow to obtain a wire of smaller diameter than the industry produces. However, the significant problem is the increase of the strain induced roughness of wire during dieless drawing. This problem has become important due to the fact that the resulting roughness can be comparable to the diameter of the wire and significantly reduce the workability. Thus, the solution of these problems requires plastometric studies of the material, physical and numerical modeling for prediction the roughness of the wire under conditions of dieless drawing. The experimental study shown, that the surface roughness of the copper wire after dieless drawing increases significantly at a deformation temperature above 300°C. The total roughness is associated both with the formation of oxides and the strain induced roughness.