Wire Feed Speed Research Articles

Drop and hump behaviors in robotic arc-directed energy deposition with vertical position

Arc-directed energy deposition (Arc-DED) with the vertical position offers significant potential for in-situ fabrication of overhang structures. However, the vertical position application is seriously hindered by drop and hump defects since Arc-DED possesses serious heat accumulation resulting from multi-layer depositions. The novelty of this study is to reveal the formation mechanisms of drop and hump defects in vertical Arc-DED of low-carbon steel walls. Force models of the molten pool in vertical-down and vertical-up Arc-DED are established. Two indicators, i.e., the molten pool area and the molten pool dimensional ratio, are proposed to evaluate the probability of drop and hump occurrence, respectively. Furthermore, how the wire feed speed (WFS), travel speed (TS), and the constant ratio of WFS to TS affect the molten pool behavior is explored and discussed. In the vertical-down deposition, decreasing the TS or increasing the WFS will increase the possibility of drop defects occurring when the molten pool area exceeds 45 mm². In the vertical-up deposition, increasing the TS or the WFS will increase the possibility of hump defects occurring when the molten pool dimensional ratio exceeds 4.1. Maintaining the WFS/TS constant, the probabilities of hump and drop defects increase as the WFS and the corresponding TS increase. This study offers a better understanding of the formation mechanisms underlying the drop and hump phenomena and lays a solid foundation for the practical application of vertical Arc-DED to fabricate overhang features.

Non-transferring arc and wire additive manufacturing: microstructure, mechanical properties and bulk texture evolution of deposits

PurposeThis study aims to demonstrate a modified wire arc additive manufacturing (AM) named non-transferring arc and wire AM (NTA-WAM). Here, the build plate has no electrical arc attachment, and the system’s arc is ignited between tungsten electrode and filler wire.Design/methodology/approachThe effect of various deposition conditions (welding voltage, travel speed and wire feed speed [WFS]) on bead characteristics is studied through response surface methodology (RSM). Under optimum deposition condition, a single-bead and thin-layered part is fabricated and subjected to microstructural, tensile testing and X-ray diffraction study. Moreover, bulk texture analysis has been carried out to illustrate the effect of thermal cycles and tensile-induced deformations on fibre texture evolutions.FindingsRSM illustrates WFS as a crucial deposition parameter that suitably monitors bead width, height, penetration depth, dilution, contact angle and microhardness. The ferritic (acicular and polygonal) and lath bainitic microstructure is transformed into ferrite and pearlitic micrographs with increasing deposition layers. It is attributed to a reduced cooling rate with increased depositions. Mechanical testing exhibits high tensile strength and ductility, which is primarily due to compressive residual stress and lattice strain development. In deposits, ϒ-fibre evolution is more resilient due to the continuous recrystallisation process after each successive deposition. Tensile-induced deformation mostly favours ζ and ε-fibre development due to high strain accumulations.Originality/valueThis modified electrode arrangement in NTA-WAM suitably reduces spatter and bead height deviation. Low penetration depth and dilution denote a reduction in heat input that enhances the cooling rate.

Influence of generator parameters on cutting width during WEDM process

The primary objective of this paper is to rigorously analyse the influence of selected parameters on the cut width in the context of Wire Electric Discharge Machining (WEDM). The parameters under investigation, each varied at different levels, include pulse width, servo reference mean voltage, time interval between two pulses, discharge frequency, and wire feed speed. As the workpiece material, sintered carbide K10 was used. Data for the response variable, cut width, was meticulously collected using two high-precision instruments: the Zoller Genius 3s and the Alicona InfiniteFocusSL. Among the parameters studied, the mean reference voltage emerged as the most influential variable. It holds a commanding lead with a percentage contribution of as much as 82.4 %, making it nearly 15 times more impactful than the second most influential parameter, which is pulse width. At its lowest setting, or first level, the mean reference voltage results in a record low cut width. Conversely, at its highest setting, or third level, it leads to a record high cut width. This comprehensive analysis not only quantifies the relative importance of each parameter but also provides valuable insights into the optimal settings for achieving desired cut widths. The findings have significant implications for improving the efficiency and precision of WEDM processes.

Multi-Objective Optimization for Forming Quality of Laser and CMT-P Arc Hybrid Additive Manufacturing Aluminum Alloy Using Response Surface Methodology

A thin-walled structure of high-strength aluminum alloy 2024 (AA2024) was fabricated using novel laser and cold metal transfer and pulse (CMT-P) arc hybrid additive manufacturing (LCAHAM) technology. The influence of the wire feeding speed, scanning speed, and laser power on the forming quality was systematically studied by the response surface methodology, probability statistical theory, and multi-objective optimization algorithm. The result showed that the forming accuracy was significantly more affected by the laser power than by the wire feeding speed and scanning speed. Specifically, there was an obvious correlation between the interaction of the laser power and wire feeding speed and the resulting formation accuracy of LCAHAM AA2024. Moreover, the laser power, wire feeding speed, and scanning speed all had noticeable effects on the spattering degree during the LCAHAM AA2024 process, with the influence of the laser power surpassing that of the other two factors. Importantly, these three factors demonstrated minimal mutual interaction on spattering. Furthermore, the scanning speed emerged as the most significant factor influencing porosity compared to the wire feeding speed and laser power. It was crucial to highlight that the combined effects of the wire feed speed and laser power played an obvious role in reducing porosity. Considering the forming accuracy, spattering degree, and porosity collectively, the recommended process parameters were as follows: a wire feeding speed ranging from 4.2 to 4.3 m/min, a scanning speed between 15 and 17 mm/s, and a laser power set at approximately 2000 W, where the forming accuracy was 84–85%, the spattering degree fell within 1.0–1.2%, and the porosity was 0.7–0.9%.

Microstructure and weakening mechanism of additive-manufactured Al–Cu alloy under different heat input

The heterogeneous microstructure and mechanical properties of wire-arc additive manufactured 2219 Al–Cu alloy at several heat inputs (HIs) by adjusting the wire feeding speed were investigated. The partially melted zone (PMZ) was regarded as the weak region, and the weakening mechanism was analysed. Results indicated that the size and volume fraction of equiaxial grain increased with higher HI. The mass fraction of the segregated eutectics increased and the concentration of solid solution Cu in the α-Al matrix decreased. In addition, the morphology and distribution characteristics of eutectics were distinctly different at the inter-layer zone and inner-layer zone. The eutectics at the inter-layer PMZ were coarsened and continuous owing to the Cu solid-state diffusion and liquation.

Avaliação da Influência dos Parâmetros de Processamento na Manufatura Aditiva do Aço VP50IM por PCGTAW

Abstract The wire arc additive manufacturing process or WAAM (Wire Additive Arc Welding) is recognized as a process able of making pieces of high geometric complexity, with mechanical properties comparable to those of the cast material. However, there are significant challenges associated with WAAM, such as undesirable microstructures and mechanical properties, high residual stresses and geometric distortion. This study aims to contribute to the selection of deposition parameters for VP50IM steel using WAAM via pulsed TIG (Tungsten Inert Gas) and characterization of the generated stacking, using the Central Composite Complete methodology, CCC. In this study, the peak (Cp) and base (Cb) current, wire feed speed during peak (Vap), base (Vab) and welding speed (Vs) were varied. The ideal parameter presented was Cp=200A, Cb=100A, Vap=2.9cm/min, Vab=1.2cm/min and Vs=20cm/min. Tensile tests showed up to 15% greater resistance in the samples in the longitudinal section in the welding direction compared to the transverse direction. Hardness tests demonstrated up to 9% less hardness at the center of the stack compared to the top and bottom. The fracture analysis of the specimens showed ductile fracture.

Preliminarna studija geometrije navara kod navarivanja na nerđajući čelik 316l korištenjem mig postupka zavarivanja

The application of the gas metal arc welding (GMAW) process can produce metal parts in additive manufacturing (AM) and has the advantages of fast production speed and material saving. There are some different requirements for welding beads between the AM process and the usually welded joints, so preliminary research on the 316L GMAW is conducted to find the optimal voltage, wire feed speed (WFS), and travel speed (TS). Taguchi algorithm was used firstly to obtain parameters to achieve the desired higher reinforcement, lower width, and higher aspect ratio (R/W). The voltage of 19 V, WFS of 500 cm/min, and TS of 15 cm/min were obtained as the optimal one among the samples. To further investigate the influence of the parameters and verify the result, a two-factor-three-level full factorial design was carried out, with the consideration of the interaction between factors. At last, the studied parameters were used in the AM process using a GMAW welding robot to verify the reliability.

Application of synchronized tandem welding to high-hardness armor steel

Several studies have been conducted to improve combat vehicle capabilities, such as the bulletproof performance of armor and fuel efficiency through weight reduction. Titanium alloys and ceramic materials are expensive and difficult to process; therefore, they can be applied only in specific locations. In addition, arc welding, which is relatively inexpensive compared with other welding processes, is widely used in industrial fields; however, because welding is often performed in multiple passes to join one part, the productivity is reduced. Therefore, in this study, mechanical properties were investigated according to production time and heat input by applying tandem pulse gas metal arc welding (GMAW) to increase productivity. The experimental data were obtained by varying the wire feeding speed. In addition, the current–voltage waveforms were measured, and the volume shift was analyzed by comparison with images captured using a high-speed camera. To analyze the mechanical properties of the tandem weld for the welding of high-hardness armor plates, the appearance (top bead and back bead), cross-section, hardness, tensile test, impact test, and spatter generation of the welded part were analyzed. The results show that all Tank-automotive and Armaments Command (TACOM) standards for the base material were met when the tandem wire feeding speed was 11 + 11 m/min, and the single-pass process increased production speed by a factor of more than 10. Tandem pulse GMAW is shown to be a viable option for improving productivity and maintaining high-quality welds for high-hardness materials.

Investigating the microstructure and mechanical behavior of optimized eutectic Al[sbnd]Si alloy developed by direct energy deposition

Wire arc additive manufacturing (WAAM) is a direct energy deposition process majorly used to fabricate large and medium-sized components. However, the process encounters defects, such as anisotropic microstructure and mechanical properties, residual stresses, excessive oxidation, and geometrical irregularities. Hence, efforts have been made to address the issues by optimizing the process parameters and incorporating in situ and post-process treatment to improve mechanical properties. In line with this, the present work deals with statistical-based process parameter optimization based on a multicriteria approach. The responses were quantified, statistically analyzed, and correlated with the process parameters. Travel speed exhibited a minor effect on all responses, while the current and wire feed speed significantly affected the responses. The percentage porosity was more sensitive to welding current than the other parameters. The maximum ultimate tensile strength (UTS) of 193.73 ± 3.93 MPa and yield strength (YS) of 108.09 ± 12.28 were displayed by Wall 2. YS and UTS showed marginal variation in vertical and horizontal directions, while % elongation showed significant variation. The desirability Wall (DW) exhibits better-forming quality due to the minimization of the contact angle, and fibrous silicon was observed between the layers. In contrast, it appears to be fragmented silicon at the interfacial region due to remelting and breakdown of Si. However, there were a few limitations to the DW wall's mechanical properties due to coarser dendrites and bulk eutectic at the interface. The average grain size of the bottom and top region for the optimized parameter is 111.156 μm and 173.66 μm, respectively. The observed texture components in the top region include C{001} 〈110〉, A2* (111) [112¯], A (11¯1) [110], and B (11¯2) [110], exhibiting a maximum texture intensity of 10.414. In the bottom region, the identified texture components are B¯ (1¯12¯) [1¯1¯0], B (11¯2) [110], A (11¯1) [110], C{001} <110> with a maximum texture intensity of 10.110.

A functionally graded material from stainless steel 304 to Fe–40Al fabricated by dual wire arc additive manufacturing

In this study, gas tungsten arc welding (GTAW) based dual wire additive manufacturing (D-WAAM) is adopted to fabricate the functionally graded material (FGM) from stainless steel (SS) 304 to Fe–40Al, using SS 304 and aluminum alloy (AA) 1070 wires. The Al/Fe atomic ratio varies from 0 to 40 % by varying the ratio of the wire feed speeds of the SS and AA wires. The chemical composition, phases, microstructure, and mechanical properties of the FGM are investigated. The results showed that with the increase of Al content, microstructures evolve as follows: γ-Fe → γ-Fe + α-Fe → α-Fe → Fe3Al → FeAl. Cracks occur in FeAl region, caused by the high stress and the low plasticity. Dislocation walls prevent the large grains from slipping, leading to the loss of plasticity. The microhardness of SS 304 to Fe–40Al FGM ranges from 188HV0.5 to 558HV0.5. As Al content increases, the ultimate compressive strength decreases from 1820 MPa to 1061 MPa. The results on microstructure and mechanical properties provide guidance for the preparation of steel - aluminum alloy FGMs.

INVESTIGATION OF THE PROCESS OF ELECTRIC ARC METALIZATION OF COATINGS FROM STEEL 30KhGSA

The article considers the electric arc metallization technological modes of steel 30KhGSA wires, which affect thestructure formation and properties ofcoatings.Electric arc spraying was carried out using an SX-600 electric arc metallizer. The properties and characteristics of the resulting coatings depend on several plating parameters such as wire feed speed, voltage, and amperage. The coating structure was studied by electron microscopy and metallographic analysis. The coating has a layered structure, which consists of frozen convective metal flows, micro-welded small metal particles and oxides. The results of the study show that an increase in the wire feed speed during metallization leads to an increase in the resulting coating thickness per unit time. On the surface of steel 45, depending on the selected mode, coatings were formedfromsteel30KhGSAwithathicknessintherangefrom50μmto370μm.Ithasbeenestablishedthat when electric arc metallization coatings are sprayed with 30KhGSA wire, the microhardness of the surface layer increases by a factor of 2 relative to the microhardness of 45 steel. Based on studies investigating the impact of various factors in the electric arc spraying process on the formation of coating structures and properties, it can be deduced that utilizing electric arc metallization on steel 30KhGSA substrates allows for the production of coatings with enhanced hardness.

Arc and molten pool behavior on quality of hybrid cold metal transfer and tandem pulsed narrow gap gas metal arc welds: a study

ABSTRACT This research proposes a novel hybrid cold metal transfer (CMT) and tandem Pulsed gas metal arc welding (P-GMAW) process for narrow gap welding (NGW) of high strength low alloy (HSLA) steel plates. Investigating three sets of lead and trail wire feed speed (WFS) ratios [WFSL/T - 1.4, 1, 0.7], the study delves into the complex arc and metal transfer behavior within the narrow gap. Utilizing synchronized arc images and current-voltage waveforms, the research assesses their influence on fusion and mechanical properties. The root pass employs the single wire CMT process, while filling and closing passes leverage tandem P-GMAW, effectively minimizing incomplete fusion and reducing heat input. Results indicate that a lower WFSL/T (0.7) reduces the molten pool hump and overflow within the narrow gap while enabling direct weld arc engagement with the previously deposited layer, enhancing weld penetration. WFSL/T of 1.4 and 0.7 revealed higher and lower Charpy impact toughness.

Effective Strategies for Electron Beam Additive Manufacturing of Graded Metal Interfaces between Stainless Steel and Vanadium

This work examines the feasibility of joining two dissimilar metals, vanadium (V) and wrought Nitronic 40 stainless steel, through electron beam additive manufacturing (EBAM). Depositing V on Nitronic 40 led to mixed results with some builds exhibiting microcracking and other builds exhibiting severe cracking resulting in delamination. These build failures are thought to be caused by a large coefficient of thermal expansion (CTE) mismatch and solubility issues, demonstrating the challenges associated with this material combination. The large melting temperature discrepancy between Nitronic 40 and V was thought to exacerbate the issues with CTE mismatch and solubility. Four strategies could be employed by EBAM to mitigate the observed issues to successfully deposit V on Nitronic 40: (1) adjust wire feed speed, (2) use dual wire feeders, (3) use different wire feedstocks to control composition, and (4) create a transition layer known as buttering to accommodate CTE mismatch.

Parametric investigation on wire arc additive manufacturing of ER70S-6 low-carbon steel for fabrication of thick-walled parts

This study explores the influence of various parameters on bead profiles within the wire arc additive manufacturing (WAAM) process, specifically focusing on ER70S-6 low-carbon steel to produce thick-walled parts. The critical geometric characteristics under scrutiny are bead width (BW) and bead height (BH), with the primary goal being optimization. The research methodology incorporates the utilization of the Taguchi method, analysis of variance (ANOVA), regression modeling, and grey relational analysis (GRA) to scrutinize and enhance process parameters. The results reveal that a rise in wire feed speed (WFS) from 5 to 8 m/min and voltage (V) from 18 to 24 V leads to a substantial increase in BW, with contributions of 79.90% and 4.77%, respectively, according to ANOVA. Conversely, a rise in traverse speed (TS) from 0.3 to 0.6 m/min results in a reduction in BW by 11.90%, while the impact of gas flow rate (GFR) is relatively minor. Regarding BH, a rise in WFS within the 5–8 m/min range significantly enhances BH, with an ANOVA contribution of 17.78%. In contrast, higher voltage and TS lead to a reduction in BH, with TS exhibiting the dominant influence at 46.08%, followed by voltage at 31.13%, and WFS at 17.78%. The GFR exerts a negligible impact at 0.88%. To address the challenge of multi-objective optimization, GRA is proficiently employed, resulting in recommended process parameters for BW and BH: WFS = 8 m/min, V = 18 V, TS = 0.3 m/min, and GFR = 18 L/min. These results are robustly validated through experimental verification, affirming the accuracy of predictive models.

A Study on Gap Bridging Formation Conditions in Butt Root Pass Welding Using GTAW

GTA welding is a representative welding technique applied to root pass welding of piping. The pipe root pass welding significantly influences the determination of welding parameters owing to the root gap and step change occurring during installation. GTA welding has the advantage of being able to control current (A) and wire feeding speed (WFS) as independent variables; however, determining these variables is difficult. In this study, the change in the back bead height (Bbh) was observed by changing the root gap and WFS while the welding speed and welding current (A) were fixed. By fixing the welding speed and changing the welding current (A), root gap, and WFS, the gap bridging possible condition was expressed as a region. When the root gap changed from 0~1 mm and from 1~2 mm, the back bead height was greater than or equal to 0 mm. Possible welding current and WFS and the setting range of the welding heat input ratio (HIR) were presented.

Study on the Relationship between Process Parameters and theFormation of GTAW Additive Manufacturing of TC4 Titanium Alloy Using the Response Surface Method

The geometric parameters of the deposited layer include the width, height, and penetration depth of the deposited layer. The welding current, wire feeding speed, and torch travel speed during the additive manufacturing process of TC4 titanium alloy have the greatest impact on the geometric parameters of the deposited layer. In order to study how the deposition layer width, deposition layer height, and penetration depth are affected by the welding current, wire feeding speed, and torch travel speed, this article uses Design Expert 8.0.6 software for Box−Behnken design response surface experiments. During the experimental design, the welding current, wire feeding speed, and torch travel speed are used as input variables. The deposition layer width, deposition layer height, and penetration depth are selected as the responses. We designed 17 response surface experiments that were conducted using GTAW-AM. The results show that as the welding current increases, the penetration depth and width of deposition layer gradually increase, and the deposition layer height gradually decreases. As the wire feeding speed increases, the deposition layer height and penetration depth gradually increase, and the wire feeding speed has a minimal effect on the deposition layer width. As the torch travel speed increases, the penetration depth, width and height of deposition layer gradually decrease. The response surface method experimental design can also optimize the matching of three process parameters: welding current, wire feeding speed, and torch travel speed, thereby obtaining the optimal matching range of process parameters. Within the optimized matching range of process parameters, a welding current of 90 A, a wire feeding speed of 900 mm/min, and a torch travel speed of 200.18 mm/min were selected to prepare TC4 titanium alloy thin-walled part. The microstructure of the top, middle and bottom are all basketweave structure. The α phase gradually becomes coarse from the top to the bottom. The microhardness of the top, middle, and bottom of the thin-walled parts is 362.7 HV, 352.7 HV, and 340.5 HV, respectively. The horizontal tensile strength is 926.1 MPa, with an elongation of 12.22%, and the vertical tensile strength is 938.1 MPa, with an elongation of 14.41%.

Effects of deposition height stability of CuCrZr alloy based on arc voltage sensing: Influence of materials and energy saving on wire arc additive manufacturing

Wire arc additive manufacturing (WAAM) is a promising process technology to produce large-size metal parts. Nevertheless, it is a challenging task to deposit Cu alloys by WAAM due to their high thermal conductivity. Poor quality of geometry and height stability result in significant material waste and energy consumption. In this paper, a control system based on arc voltage sensing was developed for monitoring and controlling the deposition progress of CuCrZr alloy. An empirical mode decomposition (EMD) filtering method was used to filter out the random noise in the original arc voltage signals. A novel dual control method combining height lifting control and iterative learning control was proposed, where the lifting height and wire feed speed were used as manipulated variables and the arc voltage was the controlled variable. The effectiveness of control system was tested through the deposition of single-channel multi-layer thin walls. Compared with the conventional method, the energy input is reduced by 28.7%, and the effective material forming utilization is increased by 50.0%. More stable arc voltage and better forming quality indicate that arc voltage sensing and dual control method are effective in improving height stability and enhancing material and energy utilization.

Influence of Wire Feed Speed and Torch Speed on the Mechanical Properties of Wire Arc Additively Manufactured Stainless Steel

Abstract Wire arc additive manufacturing (WAAM) enables 3D printing of large high-value metal components. However, integrating WAAM into production lines requires a critical understanding of the influence of process parameters on the resulting material characteristics. As such, this research investigates the relationship between WAAM wire feed speed (WFS) and torch speed (TS) on the resulting mechanical characteristics of 316LSi thick parts (2.5 cm (0.98 in.)). The experimental procedure is informed by a training matrix that allows parametric analysis of WFS and TS on the ultimate tensile strength (σult), yield strength (σy), elastic modulus (E), failure strain (εf), hardness (HV0.5), and dimensional accuracy (Da) of the printed samples. The research found that WAAM-processed 316LSi parts feature isotropic material properties despite variations in WFS and TS. The surrogate model developed in this study offers five significant polynomial models capable of accurately predicting the influence of WAAM process parameters on σult, σy, εf, E, and Da. The research found TS to be the most significant WAAM process parameter in comparison to WFS for σult and εf. On the contrary, σy, E, and Da were found to be primarily driven by WFS as opposed to TS. Overall, the paper for the first time presents an accurate surrogate model to predict the mechanical characteristics of WAAM 316LSi thick parts informed by wire feed speed and torch speed. The study demonstrates that the mechanical properties of WAAM-processed steel are primarily influenced by the underlying process parameters offering significant potential for tunable performance.

Parameters prediction in additively manufactured Al-Cu alloy using back propagation neural network

The relationship between tensile strength, wire feeding speed and travel speed is built based on Back Propagation (BP) neural network during the wire arc additive manufacturing (WAAM) process. The introduction of a genetic algorithm for optimising the BP neural network (GA-BP) and incorporation of additional parameter combinations through the forward model markedly enhance the prediction accuracy of the process parameter reverse model. The BP neural network with a genetic algorithm model exhibits excellent training results, and the sample population regression reaches 0.97. An error value of the optimised model is only 3.10% for wire feeding speed prediction, only 1.55% for travel speed prediction. The GA-BP reverse model optimises WAAM process parameters and achieves a tensile strength exceeding 230 MPa.

Characterization of cold metal transfer and conventional short-circuit gas metal arc welding processes for depositing tungsten carbide-reinforced metal matrix composite overlays

This paper compares the processing characteristics of advanced CMT (cold metal transfer) and conventional GMAW-S (gas metal arc welding with short-circuit metal transfer) processes for depositing Ni-WC MMC (nickel-based metal matrix composites reinforced with WC) overlays. In contrast to common expectations, advanced CMT technology with mechanically assisted droplet transfer could not demonstrate significant advantages over the GMAW-S process; on the contrary, CMT exhibits marginal disadvantages in terms of carbide transfer efficiency, volume fraction of retained WC, and deposition rate. Some carbides originally contained in the core of the feed wire are blown away and expelled out of the processing zone leading to physical losses of WC particles during the deposition processes, which is more significant for the CMT process owing to much higher waveform cycle frequency and cyclic feed wire retractions. CMT exhibits superior waveform stability, better control over penetration depth, marginally lower dilution level, and exceptional arc stability. The main parameters affecting carbide transfer efficiency and volume fraction of retained WC are wire feed speed and travel speed for both processes; increased wire feed speed and travel speed generally lead to decreased carbide transfer efficiency and reduced volume fraction of retained WC. Shielding gas may have different effects on the outcomes for the CMT and GMAW-S processes. CMT overlays show comparatively higher W and lower Fe concentration in the matrix, while GMAW-S overlays show a higher concentration of Fe in the matrix (due to elevated dilution level) with marginally higher matrix microhardness and more herringbone-like secondary carbide precipitates.