Wire Manufacturing Research Articles

Location-dependent microstructure analysis and mechanical behavior of inconel 625 using Cold Metal Transfer(CMT) based wire and arc additive manufacturing

Wire and Arc Additive Manufacturing(WAAM) is an emerging economic fabrication method to produce components with complex features. Inconel 625 (IN625) is a nickel-based super alloy with high strength and corrosion resistance at elevated temperatures. A single-walled Inconel 625 part was fabricated using a cold metal transfer(CMT) based WAAM process. This study focuses on location-based microstructure and mechanical analysis of a WAAM-printed wall. Three regions were analyzed, i.e., Top, Bottom, and Middle. The results show that the grain morphology varies with different locations. The texture {001} <001> is identified as preferred grain orientation using Electron Backscatter Diffraction(EBSD) analysis. The X-Ray Diffraction(XRD) analysis depicts the variation in peak intensity for different samples, and the γ-Ni FCC phase is only detected in all samples. The tensile strength is higher for the horizontal sample, and elongation is higher for the vertical sample. The microhardness values decrease with increasing height.

Comparative Life Cycle Assessment of the Manufacturing of Conventional and Innovative Aerators: A Case Study in China

China aims to achieve a 50% rate of mechanization for aquaculture by 2025. Aerators are crucial mechanical equipment in aquaculture for increasing yield, but their manufacturing has an environmental impact. Improving the yield and controlling the environmental impacts of aerators in China is an important issue have to be considered, as is comparing the environmental impact of manufacturing innovative and conventional aerators. Herein, life cycle assessment (LCA) as a quantitative analysis method was used, and six models of three widely used aerators (impeller, paddle wheel, and wave) were selected as an example to compare the environmental impacts of conventional and innovative aerators from large-scale aerator manufacturing enterprises in Taizhou, China. The results showed that the conventional paddle wheel aerator (SC-1.5) had the largest environmental impact, while the innovative paddle wheel aerator (GSC-1.5) had the lowest environmental impact, reduced by 30%. In addition, the environmental impact of the innovative impeller aerator (SYL-1.5) and wave aerator (GYL-1.5) was less than that of the conventional impeller aerator (YL-1.5) wave aerator (SW-1.5), but only by 0.21% and 0.02%, respectively. Human toxic potential (HTP) made the largest contribution, and the manufacturing of copper wire was critical; the environmental impact was from 96.50% to 98.21% for all material inputs. The contributions of iron and stainless steel were 1.05–1.28% and 0.74–1.04%, respectively. Therefore, conductive materials with excellent environmental performance, such as carbon nanomaterials and nano copper wire, should replace copper wire in aerator manufacturing. The results expand aquaculture life cycle knowledge and could reduce the environmental impacts of aerator manufacturing in China.

An in situ surface defect detection method based on improved you only look once algorithm for wire and arc additive manufacturing

Purpose Wire and arc additive manufacturing (WAAM) is a widely used advanced manufacturing technology. If the surface defects occurred during welding process cannot be detected and repaired in time, it will form the internal defects. To address this problem, this study aims to develop an in situ monitoring system for the welding process with a high-dynamic range imaging (HDR) melt pool camera. Design/methodology/approach An improved you only look once version 3 (YOLOv3) model was proposed for online surface defects detection and classification. In this paper, improvements were mainly made in the bounding box clustering algorithm, bounding box loss function, classification loss function and network structure. Findings The results showed that the improved model outperforms the Faster regions with convolutional neural network features, single shot multibox detector, RetinaNet and YOLOv3 models with mAP value of 98.0% and a recognition rate of 59 frames per second. And it was indicated that the improved YOLOv3 model satisfied the requirements of real-time monitoring well in both efficiency and accuracy. Originality/value Experimental results show that the improved YOLOv3 model can solve the problem of poor performance of traditional defect detection models and other deep learning models. And the proposed model can meet the requirements of WAAM quality monitoring.

Influence of assisted longitudinal magnetic field on the microstructure and mechanical properties of ER2319 aluminium alloy parts fabricated by wire and arc additive manufacturing

The deposit morphology, microstructure, and mechanical properties of wire and arc additive manufacturing (WAAM) of ER2319 aluminium alloy with and without assisted longitudinal magnetic field (ALMF) were investigated comprehensively and comparatively in this study. The results showed that the ALMF improved the surface forming accuracy slightly, and effectively promoted the equiaxed transformation of grains. Simultaneously, the introduction of ALMF is beneficial to improving the morphology and distribution of the strengthening phase and reducing the tendency of intergranular corrosion caused by the segregation of Cu elements along the grain boundaries. Moreover, ALMF can remarkably reduce the generation rate of large pores, thereby effectively improving the tensile strength of the deposits and reducing the anisotropy of mechanical properties.

Property profile development during wire extrusion and wire drawing of magnesium alloys AZ31 and ZX10

This paper deals with the impact of the wire manufacturing process on the mechanical property development of two magnesium alloys, AZ31 and ZX10. For this study, wires were produced with different diameters of up to 0.2 mm via direct one-step extrusion as a hot forming route and were directly compared to conventional cold drawing manufacturing routes with diameters up to 0.3 mm and associated heat-treatment. The alloy dependent microstructure development is resolved with respect to the underlying recrystallization mechanisms, which determines the texture development and concurrently the strength and ductility properties of the wires. The experimental results clearly show that the manufacturing process, the degree of deformation (wire diameter) as well as the alloy itself have a major impact on the texture development and mechanical properties of the wires. While AZ31, does not enable a strong impact on the microstructure development, ductility in ZX10 is enhanced with a concurrent weak texture development due to adjusted dynamic recrystallization during hot forming. In contrast, such microstructures cannot be adjusted in the cold forming routes due to static recrystallization. However, it is possible to improve of the properties significantly by drawing, which is limited by the first two drawing passes.

Columnar Dendrite Morphology and Solute Concentration of GH3039 Nickel-Based Superalloys during Wire and Laser Additive Manufacturing: Insights from Phase Field Simulations

Columnar Dendrite Morphology and Solute Concentration of GH3039 Nickel-Based Superalloys during Wire and Laser Additive Manufacturing: Insights from Phase Field Simulations

A profile transformation based recursive multi-bead overlapping model for robotic wire and arc additive manufacturing (WAAM)

Robotic Wire and Arc Additive Manufacturing (WAAM) is an ideal process for manufacturing large-scale or large-format parts efficiently and economically, as compared with other AM methods, and therefore finds extensive applications in diverse fields including aerospace, automotive and mould. Accurate prediction of WAAM part dimension is fundamentally dependent on the modeling accuracy of single-bead profile and its subsequent overlapping ones. This paper proposes a new recursive model, based on coordinate transformation, to predict single-layer multi-bead overlapping profile. Firstly, commonly used single-bead profile functions are reviewed, followed by detailed description of conventional and proposed recursive profile model. The properties of developed recursive model are then investigated for understanding the effects of overlapping ratio and single-bead aspect ratio. The influence of function type is also analysed from the surface quality divergence of single-layer multi-bead overlapping profile. Finally, multi-bead overlapping experimental tests are carried out to validate the feasibility of presented recursive profile model. The results show that the modified recursive model is more accurate than the conventional one for its better accountability of valley area. It is also indicated that parabola and arc function are more suitable for the robotic WAAM process. The research outcome is beneficial to improving the forming accuracy of WAAM parts, and also provides a new method for predicting geometry of other additive manufactured products.

Microstructure evolution and mechanical properties of a nickel-based superalloy repaired using wire and arc additive manufacturing

In this paper, the microstructural evolution and mechanical behaviour of the repaired ATI 718Plus sample were investigated in detail. Results show that the deposited zone (DZ) mainly contained columnar grains inclined along the z axis following the steepest temperature gradient during WAAM. And local Nb segregation leads to that a large amount of Laves, η, γ’ precipitates gathered in the interdendritic region. In contrast, the substrate zone (SZ) consisted of equiaxed grains and uniform distribution of γ’ precipitates. The γ’ precipitates in DZ show an obvious height dependence with a trend of increasing with increasing distance from the top to the bottom. Due to the exposure to elevated temperature, grain growth and the dissolution of η, γ’ phase were observed in HAZ. The hardness shows a gradual increase along the negative Z axis and an abrupt decrease in HAZ. These significant changes make the HAZ a possible vulnerable region. After direct age (DA) treatment, further growth of η precipitates and sufficient precipitation of γ’ phase were observed. The repaired samples always fractured at DZ. The tensile test indicated that UTS in DA condition shows an obvious increase, but the elongation is lower due to the brittle Laves phase acting as stress concentrators in the precipitation-hardened matrix and the fact that only half of the tensile samples experienced obvious deformation. • A defect-free repaired sample could be obtained using wire and arc additive manufacturing. • A gradient distribution of γ’ precipitates and mechanical properties were clarified. • The microstructural evolution of the deposited and substrate zones was investigated in detail. • The effect of precipitates on tensile properties under different heat treatments was discussed.

Influence of WAAM-CMT deposition parameters on wall geometry

The Wire and Arc Additive Manufacturing has called attention due to its potential in allowing the buildup of high integrity metallic parts using the commonly available welding robots in the industry. However, such a technology still presents some challenges, mainly related to obtaining optimal deposition parameters, which result in consistent layer geometry which leads to the robot and the welding power source programming. In this sense, the objective of this work is to analyze the influence of the parameters in bead and multi-layer wall geometries fabricated by the Cold Metal Transfer process to select the configurations that result in the best deposition control. The study was carried out in four steps: (i) deposition of single beads on plate, varying wire feed speed and travel speed that would result in stable and sound beads; (ii) deposition of five layer walls, considering both unidirectional and bidirectional path strategies, with and without stops between layers; (iii) deposition of ten and twenty layer walls, refining deposition parameters; and (iv) deposition of a one hundred layer wall, with the best parameter configuration among the previously tested, with bidirectional continuous strategy. The results showed that the geometry produced with a mean current of 62 A and torch travel speed of 8 mm/s along each layer and 24 mm/s on the transition between layers generated the best results, considering the natural cooling conditions. Also, the bidirectional path deposition presented the most regular geometries, when compared to the unidirectional strategy.

Microstructure-gradient approach for effective determination of post-heat treatment temperature of an additive manufactured Ti-6Al-4V sample

In this paper, a Ti-6Al-4V wall was fabricated using wire and arc additive manufacturing to be as-deposited (AD) coupons for investigating the effect of post-heat treatments on microstructure and mechanical properties. A Gleeble thermal-mechanical simulator was used to create a microstructure gradient in the sample with different heat treatment temperatures to efficiently determine the optimal post-treatment temperature, which is followed by furnace heat treatments to find proper aging (Age) conditions. Solid solution at 830 ℃ for 2 h followed by water cooling + aging at 500 ℃ for 4 h followed by furnace cooling was considered to be the optimal post-heat treatment candidate because it gained a 12.85% improvement of yield strength (YS) and 3.33% improvement of the ultimate tensile strength (UTS), though tensile fracture elongation (EL) decreased 3.37% compared to the as-deposited samples. With this condition, microstructure evolution including β grains, α widmanstätten, grain boundary α (GB α), and α’ martensite was characterized at the same position of the sample experienced deposition (AD), solid-solution treatment (AD-ST), and aging (AD-ST-Age) respectively. The relationship between such step-by-step microstructure evolution with tensile strength as well as hardness change was analyzed and established. In the end, brittle fracture surfaces of AD, AD-ST, and AD-ST-Age samples were observed to find the factors that contribute to failure.

Recovery of Hydro Turbines: From Welding to Additive Manufacturing

This work describes the advances in manufacturing for the recovery of hydraulic turbines. One of the key components in the operation of hydraulic turbines is the blades; as they are part of the impeller, they are in constant motion and directly receive all the loads produced by the impact of the water and the abrasive effects caused by sediment. The interaction between abrasion, cavitation, and corrosion accelerates the wear of these components, so it is necessary to apply coatings to prolong their useful life. When these elements lose their hydrodynamic profile, they must be submitted to a recovery process; typically, welding is used. However, due to the advancement of additive manufacturing (AM) and the development of new materials, AM appears as a disruptive technology capable of recovering the dynamic profile and improving surface properties such as hardness and wear resistance. The results show the effectiveness of the wire and arc additive manufacturing technology for the recovery of hydraulic turbines, increasing surface hardness from 285 to 325 HB.

Non-uniform high-temperature oxidation behavior of twin wire and arc additive manufactured Ni3Al-based alloy

Ni3Al-based alloy fabricated by twin wire and arc additive manufacturing exhibited periodic remelting bands (RB) with unique microstructural characteristics. In this work, the deposited Ni3Al-based alloy was oxidized at 1100 °C for different times to investigate the high-temperature oxidation difference caused by RB. The differences in the microstructure, grain orientation, oxidation behavior, and oxidation mechanism between RB and non-RB were systematically studied. The results showed that these RB, epitaxially grown on the non-RB during each deposition layer, displayed similar Goss textures but a higher proportion of γ + γ′ dual-phase microstructure compared to non-RB. The oxidation of the deposited Ni3Al-based alloy obeyed parabolic growth kinetics at 1100 °C for 10 h and the oxidation scales were consisted of external NiO layer, intermediate NiAl2O4 layer with dispersed Al2O3 and TiO2 particles and internal Al2O3 layer. The outward diffusion of Al and Ti elements during the oxidation process led to the decomposition of γ′ precipitations and the formation of γ′-reduced layer beneath the Al2O3 layer. The cross-section microstructure of oxidation scales indicated that the RB displayed thicker scales and poorer oxidation resistance than non-RB. The oxidation rate of the deposited Ni3Al-based alloy was controlled by the outward transport rate of the total cations (Ni2+, Al3+, and Ti4+) through the Al2O3 layer. Initial oxidation and diffusion interface analysis demonstrated that the γ + γ′ dual-phase had a higher outward transport rate of the cations, which was responsible for the thicker oxide scales on the RB.

Estimation of critical thickness of insulation for regular polygon cross-section ducts/conductors

In some areas, due to geometry or space constraints, the outer structures of ducts or conductors are non-circular or are of regular polygonal shape. Determination of critical thickness of insulation for these ducts or conductors is difficult. The critical thickness of insulation, in case of circular cross section duct depends on the thermal conductivity of the material and heat transfer coefficient surrounding the duct. Authors in this work have attempted to estimate the critical thickness of insulation in case of regular polygonal cross-section. It is attempted to determine the critical thickness, leading to maximum heat loss, in case of various polygonal cross section. In this work the authors have estimated a correction factor that can multiplied to the critical thickness if the conductor is circular in cross section. It is observed that correction factor goes on increasing as the number of sides goes on increasing. The proposed work is relevant to the heat transfer community. Wire and solar plate manufacturers will be directly benefited from the outcome of this project to improve their design.

Microstructural Investigation of a FeMnAlNi Shape Memory Alloy Processed by Tungsten Inert Gas Wire and Arc Additive Manufacturing

In the present study, tungsten inert gas wire and arc additive manufacturing was used to process an iron-based FeMnAlNi shape memory alloy. By a layer-by-layer method, a wall structure with a length of 60 mm and a height of 40 mm was generated. Bidirectional welding ensured grain growth parallel to the building direction. To maintain a nearly constant temperature–time path upon cooling, the structure was fully cooled after each weld to room temperature (298 K). With this approach, an anisotropic microstructure with a grain length of up to 8 mm (major axis) could be established. The grain morphology and formed phases were investigated by optical microscopy and scanning electron microscopy. The images revealed a difference in the orientation with respect to the building direction of the primarily formed γ grains along the grain boundaries and the secondarily formed γ grains in the heat-affected zones. Subgrains in the α matrix were observed also by scanning electron microscopy. With X-ray diffraction, the preferred orientation of the α grains with respect to the building direction was found to be near ⟨100⟩. Overall, an anisotropic polycrystalline material with a columnar texture could be produced, with a preferred grain orientation promising high values of transformation strains.

Effect of cold metal transfer mode on the microstructure and machinability of Ti–6Al–4V alloy fabricated by wire and arc additive manufacturing in ultra-precision machining

The effect of cold metal transfer (CMT) mode on ultra-precision machining (UPM) was investigated to explore phase transformation and potential improvements of surface integrity for a wire and arc additive manufactured (WAAMed)Ti–6Al–4V alloy part. Both CMT and CMT + Pulse (CMT + P) modes are taken into account, which is proved to be the stable methods to fabricate Ti–6Al–4V components. The calculation result shows that the heat input of the CMT + P mode is higher than that of the CMT mode. In the reheated conditions of the CMT + P mode, the α′ → α+β phase transformation occurs, which leads to a decrease in the number of acicular α′ martensite phases decreased and an increase in the size of the lamellar α+β phases. The UPM results showed that the cutting force increase with the cutting speed increases. In addition, the cutting force of the specimens fabricated in CMT mode is a little larger than that in CMT + P mode due to the higher strength and more α′ martensite phases. UPM can create a better surface finish with a reduction of surface roughness up to ∼90%. Moreover, the machine surface quality of the specimens in CMT mode is much better with the surface roughness of ∼0.1 μm at a low cutting speed.

Wire and arc additive manufacturing fabrication of ODS-RAFM steels and preliminary evaluation on microstructures and mechanical properties

Oxide-dispersion-strengthened reduced-activation ferritic/martensitic (ODS-RAFM) steels have promising applications in future fusion reactors, but the rapid and cost-efficient fabrication of ODS-RAFM steel components still remains a major challenge. In this study, wire and arc additive manufacturing (WAAM) techniques were developed to fabricate a thin-wall ODS-9Cr-RAFM steel part, using flux cored wires containing nano-Y2O3 as the [Y] and [O] sources and Ti as micro-alloying element. Their microstructures and mechanical properties before and after austenite-quenching were both investigated, and the results were compared with other 9Cr-RAFM counterparts without the addition of nano-Y2O3 and Ti. It was suggested that Y2O3 could decompose into [Y] and [O] during the rapid melting, and then precipitate along with Ti as Y2TiO5 mostly (and perhaps also TiO2) during the rapid solidification of WAAM. These oxides have fine nano-sizes with a high number density and can provide multi-fold benefits from refining the grain/sub-grain structures, promoting martensite transformation, to pinning dislocations. After the aus-quenching, a new, more stable nano-phase of Y2Ti2O7 was formed, with combined features of ultra-fine size, high number density, and high coherency. The as-quenched ODS-9Cr-RAFM specimens can achieve markedly high strengths with good plasticity, both at room temperature and elevated temperatures up to 650 °C, showing great promises of WAAM techniques for large-scale fabricating high-performance ODS-RAFM steel structural components.

Wire and arc additive manufacturing of dissimilar 2319 and 5B06 aluminum alloys

• Fracture occurred at a layer thickness above the interface layer during tensile test, regardless of the deposition order of the dissimilar alloys. • Thermal stress due to long dwell time and the remelting of S-Al 2 CuMg phase are the main factors promoting crack initiation. • Cracks mainly propagate along the aggregated pores and strip θ-Al 2 Cu phase distributed along the grain boundary. • The component deposited with bottom half of 2319 and top half of 5B06 exhibits better mechanical properties, which are approaching to that of 2319 base metal. Aluminum alloy is the most widely used light alloy at present. By combining different types of aluminum alloys, their functional properties can be expanded. In the present research, two components composed of 2319 (Al-6.5Cu) and 5B06 (Al-6.4Mg) dissimilar alloys were fabricated by wire and arc additive manufacturing (WAAM). The deposited component with the bottom half of 2319 and the top half of 5B06 exhibits better mechanical properties than its counterpart deposited vice versa. Its ultimate tensile strength, yield strength, and elongation are 258.5 MPa, 139.3 MPa, and 5.6%, respectively, which are only slightly inferior to the mechanical properties of 2319 base metal. The results show that for both components, fracture occurred at a layer thickness above the interface layer during the tensile test, regardless of the deposition order. It appears that the thermal stress due to the long dwell time and the remelting of the S-Al 2 CuMg phase are the main factors promoting crack initiation. Depending on the deposition order, cracks propagate either along the aggregated pores or strip θ-Al 2 Cu phase distributed along the grain boundary. By analyzing the heat input and selecting the appropriate depositing order, the strength of WAAM dissimilar aluminum alloys can be effectively improved through the proper control of microstructure and internal defects.

Microstructure and Texture of 2205 Duplex Stainless Steel Additive Parts Fabricated by the Cold Metal Transfer (CMT) Wire and Arc Additive Manufacturing (WAAM)

Additive parts made of 2205 duplex stainless steel were fabricated by cold metal transfer (CMT) wire and arc additive manufacturing (WAAM), and their microstructure and properties were systematically studied. The X-ray diffraction results show that austenite phase and ferrite phase were formed in the additive parts. Due to the low heat input characteristics of CMT-WAAM, no σ phase was observed. The microstructure in the additive parts was different from the bottom to the top, with the content of austenite phase gradually increasing and that of ferrite gradually decreasing. The EBSD results indicate that the ferrite phase in the bottom part grew parallel to the normal direction of {100}. However, the ferrite phase in the middle part grew parallel to the plane composed of the build direction and normal direction, and along {100} and {111}. The effect of the ferrite and austenite contents on the mechanical performance of the additive parts was simulated using the LAMMPS software. The simulation results exhibit a common characteristic in that the dislocations move mainly along the 1/6&lt;112&gt; crystallographic direction families. The simulated maximum tensile stress values of the bottom, middle, and top parts were 23.3 GPa, 22.3 Gpa, and 22.5 Gpa, respectively. The data from the bottom tensile strength simulation were consistent with the actual data, and the bottom tensile strength was the largest in the actual tensile process.

JOB SAFETY ANALYSIS ON MANUFACTURING PROCESS OF HOUSE WIRES

The objective of this project is to analysis of hazards in the process of house wire manufacturing in VGuard industries limited Coimbatore for the purpose of improving safety in the workplace and promoting safety culture among the workers. Manufacturing process involves cold wire drawing process, copper cable bunching process, Insulation process, testing and material handling process all of this process having its own significant hazards. By using the Job safety analysis technique, the analysis was carriedout and the study is submitted as a report to V-Guard industries limited Coimbatore. Here the proposed practical solution in the sequence of Elimination, Substitution, Engineering control, Administrative control, and Personal Protective Equipment using the observation form Job Safety Analysis worksheet

Microstructural analysis of 316L stainless steel deposited by wire and arc additive manufacturing

Microstructural analysis of 316L stainless steel deposited by wire and arc additive manufacturing