Feed Speed Research Articles

Study on Welding Characteristics and Parameters of Gas Metal Arc Welding for A516 Grade 70 Steel with ER70S-6 and ER308LSi Filler Materials

Welding is a crucial process in joining metals, especially in the fabrication industry. Thisresearch aimed to investigate the effects of using two different filler materials, ER70S-6 and ER308LSi, with nine combinations of wire feeder speed (WFS) and shielding gas flow rate (GFR), on weld joints. The study focused on the weld quality and material properties of Gas Metal Arc Welded (GMAW) butt joints of ASTM A516 G70 plates, characterized through visual inspection, liquid penetrant testing, tensile testing, hardness testing, and optical microscopy. Results indicated that the highest ultimate tensile strength and hardness were achieved at 4 m/min WFS and 15 L/min GFR with ER70S-6, and 5 m/min WFS and 20 L/min GFR with ER308LSi. The specimens welded with ER308LSi demonstrated superior mechanical properties compared to those welded with ER70S-6. Additionally, the study revealed the influence of microstructural changes from the base metal (BM) to the heat-affected zone (HAZ) and fusion zone (FZ), with finer and more compact grain structures contributing to higher hardness values. These findings underscore the importance of selecting appropriate filler materials, WFS, and GFR to achieve the desired weld quality and material properties for A516 G70 low-carbon steel welded joints.

Multi-Pass Laser Welding with Cut-Wire Particles of 50 mm Thick Steel Plates

Multi-pass laser welding with filler wire feeding shows significant potential for welding thick plates. However, this method faces challenges due to the need for edge preparation and stringent control of parameters such as wire feed speed and the relative positioning to the laser beam. Utilizing cut-wire particles instead of solid wire may address these limitations. This investigated the usage of cut-wire particles in multi-pass laser welding of 50mm thick square groove butt joints. The study involved welding experiments to optimize the amount of cut-wire particles, laser power density, and travel speed for root and buildup passes. The final pass employed hybrid laser-arc welding to compensate for the voids between the cut-wire particles. The joints were successfully welded in eight passes. Mechanical testing demonstrated that the welded joints exhibited strength surpassing that of the base metal. The heat-affected zone displayed a hardness exceeding 350 HV. The fusion zones of the hybrid and buildup passes showed an impact toughness of 100J, while the root pass fusion zone exhibited an impact toughness of approximately 45J. This difference was attributed to the presence of a bainitic/martensitic microstructure in the root pass, compared to a mixture of acicular and grain boundary ferrite in the hybrid and buildup passes.

Study on heat transfer and flow of molten pool during the deposition process of laser wire additive manufacturing

In the laser wire additive manufacturing process, the molten pool acts as the critical link between the wire and the deposited part. The heat transfer and flow behavior within the molten pool predominantly determine the quality of the final deposition. Under laser power ranging from 2400 to 3000 W, traverse speeds between 0.01 and 0.04 m/s, and wire feeding speeds from 0.03 to 0.08 m/s, three distinct flow states—single-swirl, double-swirl, and no-swirl—were observed with increasing heat input. Under the optimum process parameters, the molten pool with stable temperature distribution and orderly flow was obtained. In multilayer deposition, the implementation of a laser decay strategy mitigates steep temperature gradients, diminishes the Marangoni effect within the molten pool, and effectively reduces both heat accumulation and lateral flow. Consequently, the flow mode transitions from no-swirl to swirl, and the maximum flow velocity decreases by 40%.

Dissimilar unbeveled aluminum to steel butt joint achieved by laser-arc hybrid welding-brazing

In this study, unbeveled butt joints of 2 mm thick steel and aluminum plates were welded using a laser-arc hybrid process. The influence of welding speed and wire feed speed on joint weld formation, microstructures, and mechanical properties were investigated. The results indicate that using a laser-arc hybrid heat source enables good weld formation of steel/aluminum dissimilar metals without groove preparation, even under high welding speed conditions. The steel side interface formed Fe₂(Al,Si)₅ near the steel and Fe(Al,Si)₃ near the aluminum. As the welding heat input decreased, the thickness of the intermetallic compounds gradually reduced. With an increase in welding speed or wire feed speed, the tensile strength of the joint first increased and then decreased, reaching a maximum of 104.47 MPa. Cracks propagated rapidly along the intermetallic compound region, resulting in brittle fracture characteristics. The three-point bending test showed a maximum longitudinal bending angle of 53.82° and a maximum transverse bending angle of 36.54°.

Spiral feed polishing uniform removal and compensation strategy of sapphire components

A single crystal sapphire component has been widely used in various high-tech fields because of its significant advantages such as high hardness, high stability, and excellent optical and mechanical properties, and has put forward high requirements for surface accuracy and quality. The existing sapphire polishing technology has problems such as low polishing efficiency, difficult control of polishing accuracy, and difficulty in removing surface defects and subsurface damage introduced by the front grinding process. Therefore, for the polishing and damage removal stage of sapphire optical components, the surface shape accuracy should be strictly controlled, especially for the surface shape accuracy after ultra-precision grinding. It is of great significance to study the uniform removal technology of grinding damage based on not destroying the surface shape. This study focuses on the mechanical polishing of sapphire. Firstly, the characteristics of the sapphire removal function of the elastic polishing tool are analyzed and the stability of the polishing tool is verified. Secondly, by establishing the relationship between the amount of workpiece material removal and the radius of rotation, the feed rate is planned to achieve the effect of uniform spiral removal. By optimizing the center feed speed of the tilting axis small-size polishing tool, the center feature of the polishing surface is controlled to be sharp. Finally, based on the sub-aperture polishing figuring theory, the influence of the center feature on the surface profile is reduced by using the spiral grating processing method. This study provides an efficient and stable strategy for the uniform removal and polishing of rotationally symmetric optical elements (such as aspheric surfaces) of high-hardness material sapphire and is expected to play a role in scenes that are particularly difficult to process, difficult to detect full aperture, difficult to calculate removal function and dwell time, such as higher steep aspheric surfaces and Gaussian aspheric surfaces.

Research on the reliability of wire web in diamond multi-wire saw slicing photovoltaic monocrystalline silicon wafer

Diamond multi-wire slicing technology is the main method for producing the solar cell substrate based on monocrystalline silicon. To reduce the production cost and increase the production efficiency during the sawing process, the diameter of the diamond saw wire is becoming thinner, and the sawing speed is getting faster, which leads to an increasingly prominent problem of saw wire breakage during the slicing process. To understand the breaking characteristics of diamond saw wire and evaluate the reliability of the saw wire during the sawing process, the tensile testing of saw wires was carried out in this paper. And based on the Weibull function, the breaking force was analyzed statistically. A maximum tension force model for the saw wire during the sawing process was established. And based on the maximum tension force model and Weibull reliability function, the influence of various process parameters on the reliability of the wire web was analyzed. The results indicated that as the usage time of the saw wire increases, the breaking force gradually decreases and stabilizes. Compared to the fresh saw wire, the reliability of the used saw wires is significantly reduced. As the abrasive distribution density and the wire speed increases, the reliability of the wire web gradually increases. Conversely, as the feed speed and the pretension of the saw wire increase, the reliability of the wire web gradually decrease. The results of this paper provide a theoretical approach for assessing the reliability of diamond saw wire web during the sawing process. It also provides guidance for optimizing process parameters to enhance the reliability of the wire web.

Optimization of Laser Cladding Process Parameters and Analysis of Organizational Properties of Mixer Liners

Aiming to address the wear and replacement inconvenience of concrete mixer liners, this study utilizes a laser cladding system to clad Fe60 alloy powder on the liner. It investigates the influence of different process parameters on the forming quality of the Fe60 alloy powder cladding layer. The optimal process parameters were obtained by weighted comprehensive evaluation, and single-layer multi-pass cladding experiments were carried out under the optimal process parameters to investigate the effects of a 30%, 40%, and 50% lap rate on the surface flatness and forming quality of the cladding layer. Using a metallographic microscope, a scanning electron microscope analysis of the macro morphology and microstructure of the cladding layer was conducted, a DPT-5 penetration flaw detector was used to observe the cracks on the surface of the multi-channel cladding, a microhardness tester and friction and wear experimental machine were used for the hardness of the cladding layer, and an abrasive wear resistance test was conducted. The results show that under the process parameters of a laser power of 900 W, powder feeding speed of 7 g/min, scanning speed of 600 mm/min, and 50% lap rate, the average microhardness of the fused cladding layer reaches 742 HV, which is 1.8 times higher than that of the liner plate, and the coefficient of friction is 0.57, which improves the liner plate’s wear resistance performance and service life.

Investigation of Arc Stability in Wire Arc Additive Manufacturing of 2319 Aluminum Alloy

Wire Arc Additive Manufacturing (WAAM) technology, known for its low equipment and material costs, high material utilization, and high production efficiency, has found extensive applications in the fabrication of key components for the aerospace and aviation industries. The stability of the arc is crucial for the WAAM process as it directly affects the forming of the parts. In this study, the monitoring data of electrical signals and arc morphology during the WAAM process of 2319 aluminum alloy were investigated using a high-speed camera system and current/voltage acquisition system. By analyzing the current and voltage signals, as well as the arc imaging results, the influence of arc stability on the forming of the cladding layer was studied. The experimental results indicated that when both current and voltage exhibit regular periodic fluctuations, this manifests as a stable short-circuit droplet transition form, while sudden changes in these signals represent abnormal droplet transition forms. The adaptability of the process directly influenced the arc shape, thereby affecting the forming of the cladding layer. Under the process parameters of welding speed of 240 cm/min and wire feeding speed of 6.5 m/min, it was observed that the current signal exhibited a tight state and the variance of the arc width was minimized. This indicated that at a higher wire feeding speed, the droplet transfer frequency was increased. Under these process parameters, the arc output was more stable, resulting in a uniform metal coating.

Kalibrasi Wire Feeder Flux Core Arc Welding (FCAW) Mengacu Pada Standar British Standard (BS) 7570:2000 Dan British Standard (BS) European Standard (EN) 50504:2008

In the fabrication industry, the welding process plays a crucial role in both engineering and repair production processes. Continuous use of welding machines can lead to a decline in their effectiveness. Suboptimal machines may produce low-quality products. A common issue encountered is the poor quality of welds, even when each step has been aligned with the Welding Procedure Specification (WPS). One source of this problem is the welding equipment itself. The objective of this study is to calibrate arc welding equipment to ensure it remains within machine standards. Calibration is performed in accordance with BS EN 50504:2008 and BS 7570:2000. The calibration focuses on measuring constant voltage and wire feed speed (WFS). The measurement results for WFS variation indicate that it does not exceed a 10% error margin. This suggests that the WFS complies with the established standards. Consequently, the Lincoln LN-25X wire feeder speed is ready for use in fabrication and production processes.

Prediction Models for the Milling of Heat-Treated Beech Wood Based on the Consumption of Energy

This article is focused mainly on verifying the suitability of data from the experimental milling of heat-treated beech wood and on investigating the effects of the technical and technological parameters of milling on the energy consumption of this process. The independent parameters of the machining process are the cutting speed, feed speed, rake angle, and hydrothermal modification of the experimental wood material. Based on analysis of variance, it can be argued that the cutting speed and rake angle of the tool have the greatest statistically significant effect on energy consumption, while the feed speed has the least influence. The measured data on cutting power during milling were used to build a regression model and validate it, and the most suitable type of model, with a correlation of 87%, is the classification and regression tree, followed by a model created using the random forest method.

Influence of Printing Parameters on the Morphological Characteristics of Plasma Directed Energy-Deposited Stainless Steel

This study investigated the influence of printing parameters and strategies on the morphological characteristics of austenitic stainless steel beads deposited on carbon steel substrates, using plasma directed energy deposition (DED). The experimental setup varied the welding current, wire feed speed, and torch travel speed, and we analyzed three printing strategies: simple-linear, overlapping, and oscillating. Moreover, advanced 3D scanning and computational analysis were used to assess the key morphological features, including bead width and height. The results showed that the computational model developed by using parabolic assumptions accurately predicted the geometric outcomes of the overlapping beads. The oscillating printing strategy was the one that showed improved morphological uniformity and bead substrate wettability, so these features were used for multi-layer component manufacturing. The use of equivalent wavelength–amplitude values resulted in maximum combinations of bead height and width. Moreover, cost-effective carbon steel substrates were feasibly used in microstructural and elemental analyses, with the latter ones confirming the alignment of the bead composition with the wire-fed material. Overall, this study provides practical insights for optimizing plasma DED processes, thus enhancing the efficiency and quality of metal component manufacturing.

Improving microstructure and mechanical properties of WAAMed Al with UV introduced via a torch clamp

Abstract Ultrasonic assisting is considered to be a promising technology for industrial applications due to its ability to improve the quality of the WAAMed component. A specially designed ultrasonically vibrating torch clamp (UV torch clamp) was used to introduce the UV in the WAAM process of Al alloy for the first time. UV effect on the forming accuracy, microstructure and mechanical properties of WAAMed Al thin-walled component were investigated. The results show that the UV applied via the UV torch clamp changed the metal transfer mode, and increased the transfer frequency by at least 7.42% compared with that without UV at various Wire Feed Speed (WFSs). The applied UV caused slight increases in the surface roughness of the deposited thin-wall components at low WFSs and obvious decreases at high WFSs, the most significant reduction occurred with WFS = 8 m min−1, the surface roughness decreased from 1.04 to 0.44. The grain size and the pore size and density in the deposit were significantly reduced by the UV, and the higher the WFS, the greater the grain refinement effectiveness and the pore suppression effectiveness. The UTS and fracture elongation of the specimen with UV application increased by at least 4.6% (from 277 Mpa to 290 Mpa for longitudinal specimen with WFS = 5 m min−1, ) and 3.3% (from 21.42% to 22.12% for vertical specimen with WFS = 8 m min−1) respectively at various WFSs compared to the specimen without UV application.

Overcoming the Strong Sample Solvent Effect for Sustainability Measurement Challenges in Liquid Chromatography. Example for Bisphenol-A.

This paper describes an approach to achieve low parts per billion (ppb) concentration level detection using a reversed-phase ultrahigh-performance liquid chromatographic ultraviolet absorbance detection method with large-volume feed injection (FI) for analytes in dichloromethane (DCM). FI is a novel technology that allows sample injection at a defined speed into the LC mobile phase. We demonstrate this approach for a mixture of bisphenol A and its diglycidyl ether derivatives in DCM. DCM is a very strong injection solvent at reversed-phase LC conditions and is typically immiscible with a starting reversed-phase gradient mobile phase containing a high percentage of water. As a result, reduced separation performance and even peak splitting are seen with classic flow-through injection. The method setup comprised an octyl-bonded core-shell stationary phase (150 × 4.6 mm i.d., 2.7 μm particle size) with a water/acetonitrile mobile phase gradient and an exceptionally high injection volume of 45 μL of DCM solution using FI. Optimization of feed speed (1%) and isocratic hold duration (4 min) was crucial for final separation conditions. FI delivered more than a 20-fold improvement in the limit of detection (LOD) compared to standard flow-through injection while maintaining peak resolution. The LOD of the final method ranged between 1 and 10 ppb in the polymer resin. This methodology has high potential for trace analysis in a large variety of applications that suffer from the "strong solvent effect".

Fabricating complex parts through optimizing weld bead geometry in WAAM: A comparative study of surface tension transfer and cold metal transfer

Wire arc additive manufacturing (WAAM) technology is being employed in industries such as aerospace, maritime and automotive to produce high-valued metallic parts. With a growing demand for products with complex structures, it is crucial to develop an effective and reliable method for fabricating such parts to meet the demand. Currently, cold metal transfer (CMT), is one of the waveform-controlled short circuit transfer processes, commonly adopted in the WAAM process to fabricate medium to large-scale parts due to its perceived low heat input. However, the approach of using synergic control of wire feed speed and torch travel speed to control weld bead geometry in CMT may not be applicable for fabricating parts with complex structures. In these circumstances, surface tension transfer (STT), a waveform controlled short circuit transfer process, or one of the alternative variants of controlled short circuit transfer with low heat input, may provide more options to control weld bead geometry. There appear to have been few systematic investigations of alternative controlled short circuiting variants for use in WAAM. This paper provides a comparative study to explore the potential of the STT process for fabricating parts with complex geometries in WAAM. Firstly, the working principles of the STT and CMT processes are reviewed. Then, the impacts of welding parameters in the STT and CMT on weld bead geometry are analysed based on experiment results. Finally, a comparison between these two welding processes with regard to flexibility in welding parameter adjustment, heat input and overlapping performance is conducted. Finally, a comparison between these two welding processes is conducted from three critical aspects: (i) Flexibility in parameter adjustment: STT has 333 % and 174 % larger average width and height variation ranges than CMT; (ii) Heat input: STT's heat input is 74.66 % higher than CMT's at TS = 300 mm/min; (iii) Overlapping performance: the average surface roughness of the tested CMT and STT groups is 0.1312 and 0.1823, respectively. Suggestions for using STT and CMT to fabricate parts with complex geometries are provided accordingly.

Research on grinding parameter optimization based on adhesive semiconductor quartz disc

Abstract To study the influence of grinding parameters on the grinding force of semiconductor quartz disc based on the adhesive clamping method, an orthogonal experiment was designed to investigate the impact of grinding parameters on the grinding force. Based on the orthogonal test data, the influencing factors and parameter optimization of the grinding force are developed. The experimental results show that the order of influence of grinding parameters on the X-axis is feed speed > spindle speed > grinding depth, the sequence of effect on the grinding force in the Y-axis is grinding depth > feed speed > spindle speed, and the order of influence on the grinding force in Z-axis is grinding depth > spindle speed > feed speed. Therefore, using a higher spindle speed, a lower feed rate and a shallower grinding depth can play a role in reducing the grinding force. By improving the grinding parameters, the stability of quartz plate grinding based on adhesive technology is verified. It is found that adhesive is a more reliable clamping method, which ensures the processing quality of quartz plate and improves the working efficiency.

Experimental Study on Surface Residual Stress and Surface Roughness of Inconel718 Cutting

Abstract This thesis focused on the experimental study of surface residual stress and surface roughness of Inconel718 for cutting processing. Based on cutting theory, the cutting parameters’ effects on surface residual stress and roughness were analyzed through single-factor cutting experiments. The experimental results showed that: in the experimental parameters under constant conditions, Inconel718 processing surface residual stress with a rise in cutting speed in gradual decrease, with a rise in feeding speed and cutting depth in gradual increase; processing surface roughness Ra and Rz value with a rise in cutting speed in gradual decrease, with a rise in feeding speed and cutting depth in gradual increase. Consequently, the experimental results for Inconel718 cutting and processing technology provide a process basis.

Experimental study on decarburization of fine fly ash by electric separation

ABSTRACT The effect of rotary triboelectric separation parameters on decarburization of fly ash was systematically studied to prove that the technology was an effective means to purify fly ash. The results showed that obvious mismatch of carbon particles occurs when separation voltage was greater than 25 kV, while mismatch of other mineral particles was generated when separation voltage was greater than 30kV; The decarburization effect of fly ash could be significantly reduced due to the decrease of particle surface charge density when the feed frequency was greater than 20 hz. The feed was also affected by the speed and direction of the particle feed, the closer to the middle of the feed port, the higher the probability of the particle being effectively separated; when rotation speed of the friction wheel exceeded 4000 r/min, the particle mismatch in the separation chamber becomes more and more obvious. In addition, the speed of the friction wheel also affected flow field in separation chamber, which may have an adverse effect on separation effect; Co-flow velocity affected retention time of particles in the separation chamber. 6 m/s is the best co-flow velocity for fly ash decarburization. In this case, the flow field generated by the co-flow is uniform to ensure stable transport of particles.

CFD-DEM simulation and experimental validation of air classification for tobacco particles

In cigarette processing, the challenge is particularly significant during the air classification of tobacco and stems due to their similar characteristics. This paper employs computational fluid dynamics (CFD) combined with the discrete element method (DEM) to analyze factors affecting separation efficiency and improve performance. The results were validated through laboratory and production line experiments at a 1:1 scale. The tobacco (length: 0 mm–4.75 mm, diameter: 0.32 mm) and stem (length: 0–25.145 mm, diameter: 1.51 mm) were modeled based on production samples. Findings suggest that particle feeding speed primarily impacts tobacco loss rate, while inlet air velocity mainly influences stem removal rate. Optimizing the chamber structure in the simulation resulted in a 63.66 % improvement in separation efficiency. Airflow streamlines, particle distribution, trajectory, and collision behaviors were discussed to illuminate motion characteristics. The flexible particle model moderately influenced separation efficiency and collision behaviors. These insights enhance the understanding of particle separation and the design of separation devices.

Improvement of wire marks on the surface of Si3N4 ceramics cut by diamond wire saw

The presence of wavy wire marks on the cut surface of silicon nitride (Si3N4) ceramics reduces the mechanical properties of the slices and increases the workload of subsequent grinding and polishing processes. To improve the wire marks, a workpiece reciprocating movement-assisted diamond wire sawing (RMA-DWS) technology is proposed in this paper. While diamond wire sawing the Si3N4 ceramics, the workpiece is moved back and forth in the direction of the saw wire movement to assist in sawing. Single factor and orthogonal experiments were carried out to analyze the characteristics of the surface created by this sawing technology. The effects of workpiece reciprocating movement distance, workpiece reciprocating movement speed, saw wire speed and feed speed on the sawn surface morphology, surface roughness Ra and wire marks PV value, as well as the primary and secondary relationships of the effects, were investigated. And the optimal parameter combinations were explored. The results show that within the range of process parameters studied in this paper, the surface morphology of Si3N4 ceramics slices shows a comprehensive effect of material ductility and brittleness removal, the RMA-DWS technology can improve wire marks on the slice surface. Surface wire marks PV value can be reduced by increasing the workpiece reciprocating movement distance and saw wire speed, reducing the feed speed, while increasing the reciprocating movement speed of the workpiece, the PV value shows a trend of first decreasing and then increasing. The variation amplitude of surface roughness Ra value is not significant, and the variation trend is roughly similar to the change trend of PV value. It was determined that the experiment with the process parameters combination of 0.1 m/min feed speed, 90 mm workpiece reciprocating distance, 15 mm/s workpiece reciprocating speed and 1400 m/min saw wire speed yielded the optimal result, significantly improving the wire marks of the sliced surface. The results of this paper provide ideas for the development of sawing wire marks improvement technology.

Prediction of surface roughness at the machining of densified wood surfaces

ABSTRACT In this research, modeling and interpretation of the effects of the machining parameters on surface roughness (Rz) using artificial neural networks (ANN) and analysis methods (MLP, LVQ and Taguchi Design analysis) werw studied. Black poplar (Populus nigra) was selected as the experimental material. Specimens, which were transversal densified by a thermo-mechanical (TM) process at 0%, 20% and 40% compression ratios. The densified wood was processed at 1000, 1500 and 2000 mm/min feed speeds and in 12,000, 15,000, and 18,000 rpm rotation speeds in a CNC machine by using two different cutters. Rz surface-roughness values were measured. The modeling of Rz with artificial neural networks (ANN) is discussed. While 97% success was achieved in the classification made with multilayer perceptron (MLP) in estimating Rz, this success rate is 100% in the classification made with learning vector quantization (LVQ). MLP and LVQ are operations in the MATLAB R2019b software. Taguchi values were compared with the experimental data results, it was seen that the MSE value was 4.6%, the MAE value was 1.8%, and the RMSE value was 2.1%. These results showed that the presented models can accurately determine the appropriate parameters for the desired Rz. The prediction results and presented models can be applied for targeted industrial applications.