Magnetic Arc Oscillation Research Articles

Corrigendum to “Mechanism of corrosion protection in reinforced Ti-6Al-4 V alloy by wire arc additive manufacturing using magnetic arc oscillation Volume 199 (2023) 112844.”

Corrigendum to “Mechanism of corrosion protection in reinforced Ti-6Al-4 V alloy by wire arc additive manufacturing using magnetic arc oscillation Volume 199 (2023) 112844.”

Mechanism of corrosion protection in reinforced Ti-6Al-4 V alloy by wire arc additive manufacturing using magnetic arc oscillation

Mechanism of corrosion protection in reinforced Ti-6Al-4 V alloy by wire arc additive manufacturing using magnetic arc oscillation

Enhanced corrosion performance in Ti-6Al-4V alloy produced via wire-arc directed energy deposition with magnetic arc oscillation

Enhanced corrosion performance in Ti-6Al-4V alloy produced via wire-arc directed energy deposition with magnetic arc oscillation

The Effect of GTAW Variants on Tensile and Microstructural Properties of AZ31B Magnesium Alloy Joints

In this investigation, an attempt is made to study the tensile and microstructural impact of different gas tungsten arc (GTA) welding processes of pulsed current, constant current, and magnetic arc oscillation welded AZ31B magnesium metal joints. These techniques were chosen because they have the potential to produce welds with high tensile strength and excellent microstructural integrity. Five joints were produced using each approach, each one employing a unique combination of parameters. According to the findings of this experiment, the joints that were manufactured utilising a welding process called magnetic arc oscillation yielded superior tensile qualities when compared to the properties of other joints. The improved tensile characteristics of these joints can be ascribed in a large part to the creation of smaller grains and surface hardness in the transition region, as well as uniformly dispersed precipitates.

Effects of synchronized magnetic arc oscillation on microstructure, texture, grain boundary and mechanical properties of wire arc additively manufactured Ti6Al4V alloy

In this study, microstructure and mechanical properties of wire arc additively manufactured Ti6Al4V alloy with/without magnetic arc oscillation were investigated by means of optical microscopy (OM), electron backscatter diffraction (EBSD), X-ray diffraction (XRD), scanning electron microscopy (SEM), and standard tensile testing. The results show that for Ti6Al4V thin-wall components fabricated in current work, the addition of synchronized magnetic arc oscillation, including both arc oscillation and arc rotation, leads to a refinement of lamellar α width, modification of texture orientation, and then increases in low angle grain boundaries. Meanwhile, the mechanical properties (yield strength and ultimate tensile strength) of the deposition with magnetic arc oscillation are improved. The findings reveal that the arc oscillation routes can be used in wire arc additive manufacturing to create a stirring effect in deposition, which is beneficial to improvement of material properties.

Tailoring the surface finish, dendritic microstructure and mechanical properties of wire arc additively manufactured Hastelloy C276 alloy by magnetic arc oscillation

In this study, magnetic arc oscillation (MAO) at three different frequencies (5 Hz, 10 Hz and 20 Hz) was applied during deposition of a Ni-base alloy, Hastelloy C276, by wire arc additive manufacturing (WAAM). The microstructure, surface finish and the mechanical properties of WAAM deposited Hastelloy C276 alloy samples with MAO were investigated and compared with the counterpart without the application of MAO. On-line monitoring of the arc movement and molten pool morphologies showed that the incorporation of MAO during WAAM may reduce the arc density during deposition, leading to a decrease in the solidification time. This, in turn, improved the surface accuracy of the as-built alloys. Furthermore, through the application of MAO, the dendrites exhibited a higher variety of growth orientations, and reduced dendrite arm spacings (DAS). The MAO at 5 Hz appeared to enhance the mechanical properties of the produced alloy, while the application at the higher frequencies of 10 Hz and 20 Hz led to less pronounced effects on the mechanical performance improvement. This study enhanced our understanding of the correlation of MAO processing-dendritic microstructure development-mechanical property for the Hastelloy C276 alloy prepared by WAAM, providing guidelines for the utilization of the MAO approach for tailoring the microstructure and the mechanical properties of WAAM produced alloys.

The Influence of Magnetic Arc Oscillation on the Deposition Width Variation along the Length of Multi-layer Single-Pass Walls Produced by Wire Arc Additive Manufacturing Process

In this work, a wall printer system was developed, and multi-layer single-pass walls of low carbon steel were produced by the Gas Tungsten Arc Welding-based Wire Arc Additive Manufacturing process with and without Magnetic Arc Oscillation. The influence of the longitudinal oscillating movement of the welding arc during the layer deposition process on the wall geometry was evaluated using cross-sectional macrographs from samples removed from the arc striking point, arc extinguishing point, and middle of the wall. The results show that the wall becomes thinner, and the width variation along the wall length decreases when Magnetic Arc Oscillation is applied. The weld penetration also becomes less deep. A physical model based on the arc force and the magnetic force that acts on the weld pool during layer deposition was proposed to explain the influence of Magnetic Arc oscillation on the width variation noted along the wall length. Because of the alternating movement of the welding arc, the plasma jet and molten metal flow change the direction continuously. As a result, the molten metal does not concentrate at the beginning or end of the deposition length, and the width variation problem is minimized.

Effects of the welding current on the mechanical and metallurgical properties of a magnetic oscillated arc welded AZ31B magnesium alloy

Abstract In this study, the effect of current on the tensile and microstructural characteristics of magnetic arc oscillation welded AZ31B magnesium alloy joints has been investigated. Five joints were constructed using different levels of current (65 A - 85 A). It was found that the joints constructed using a current of 75 A yielded superior tensile properties as compared to the other joints. The formation of finer grains and higher hardness in fusion zone and uniformly distributed precipitates are the main reasons for the superior tensile properties of these joints.

Effects of the welding current on the mechanical and metallurgical properties of a magnetic oscillated arc welded AZ31B magnesium alloy

Abstract In this study, the effect of current on the tensile and microstructural characteristics of magnetic arc oscillation welded AZ31B magnesium alloy joints has been investigated. Five joints were constructed using different levels of current (65 A - 85 A). It was found that the joints constructed using a current of 75 A yielded superior tensile properties as compared to the other joints. The formation of finer grains and higher hardness in fusion zone and uniformly distributed precipitates are the main reasons for the superior tensile properties of these joints.

Effect of Magnetic Arc Oscillation on the geometry of single-pass multi-layer walls and the process stability in wire and arc additive manufacturing

Abstract Magnetic Arc Oscillation was applied during the construction of single-pass multi-layer walls of low carbon steel and Ti6Al4V by the Gas Tungsten Arc Welding-based Wire and Arc Additive Manufacturing process, and the influence on the geometry and the process stability was evaluated. The geometric features were assessed using transverse section macrographs and the effects of different patterns and frequencies of oscillation on the arc characteristics, metal transfer and weld pool behavior during the layer deposition were investigated using high speed and welding cameras. The results show that this technique is efficient for making thinner walls by minimizing the overflow of the weld pool and, in some conditions, increasing deposition efficiency. Furthermore, the distribution of material along the wall length becomes more homogeneous. An explanation of the effects of Magnetic Arc Oscillation on the wall geometry based on forces that act on the molten metal during layer deposition was made. Because of the swinging movement of the welding arc, the heat is distributed over a larger area, and the power density decreases. Thus, fewer previous layers are remelted, and the volume and the weight of the weld pool reduce. The weld pool temperature drops, and the surface tension force and the viscous friction increase. The distribution of arc pressure also becomes less concentrated, and the arc force on the molten metal decreases. Additionally, a magnetic force appears on the molten metal, which contributes to a change in the direction of the resultant force on the weld pool.

COMPARISON STUDY OF CONSTANT CURRENT AND ARC OSCILLATION TECHNIQUES ON GTA WELDED AZ31B MAGNESIUM ALLOY JOINTS

The challenges of achieving significant weight reduction in the automobile industry in the context of fuel savings, recyclability and emission reduction has promoted focus on lightweight metals such as magnesium. GTA welding technology is the main welding method adopted for magnesium alloys because of its advantages of utility and economy. Both magnetic arc oscillation and current pulsing techniques resulted in significant microstructural refinement in weld fusion zone. Hence in this investigation an attempt has been made to study the constant current and arc oscillation on tensile and microstructural characteristics of gas tungsten arc welded AZ31B magnesium alloy joints. From this investigation, it is found that the joints fabricated with magnetic arc oscillation having the superior tensile properties compared to constant current welding. The formation of fine grains and higher hardness in fusion zone are the main reasons for the superior tensile properties of these joints.

COMPARISON STUDY ON PULSED AND ARC OSCILLATION TECHNIQUES OF GTA WELDED AZ31B MAGNESIUM ALLOY JOINTS

The challenges of achieving significant weight reduction in the automobile industry in the context of fuel savings, recyclability and emission reduction has promoted focus on lightweight metals such as magnesium. GTA welding technology is the main welding method adopted for magnesium alloys because of its advantages of utility and economy. Both magnetic arc oscillation and current pulsing techniques resulted in significant microstructural refinement in weld fusion zone. Hence in this investigation an attempt has been made to study the arc pulsing and arc oscillation on tensile and microstructural characteristics of pulsed current gas tungsten arc welded AZ31B magnesium alloy joints. From this investigation, it is found that the joints fabricated with magnetic arc oscillation having the superior tensile properties compared to pulsed current welding. The formation of fine grains and higher hardness in fusion zone are the main reasons for the superior tensile properties of these joints

Influence of arc oscillation frequency on tensile properties and microstructural characteristics of magnetic arc oscillation welded AZ31B magnesium alloy joints

Abstract This investigation aims at assessing the impact of magnetic oscillation frequency on tensile properties and the microstructural pattern of gas tungsten arc welded with AZ31B Magnesium alloy joints. Arc oscillation frequencies ranging from 1 Hz to 3 Hz are used to form various levels of five joints. Unlike the other types joints, the joints having the base of arc oscillation frequency of 2 Hz produced greater tensile properties and it happened because of the presence of finer grains and evenly distributed precipitates in the weld region of the joints.

Effect of Welding Speed on Tensile Properties and Microstructural Characteristics of Magnetic Arc Oscillation Welded AZ31B Magnesium Alloy

Effect of Welding Speed on Tensile Properties and Microstructural Characteristics of Magnetic Arc Oscillation Welded AZ31B Magnesium Alloy

Characteristics of welding and arc pressure in TIG narrow gap welding using novel magnetic arc oscillation

Tungsten inert gas (TIG) narrow gap welding using magnetic arc oscillation is one of the most important methods for joining thick components. Today’s developments are aimed at increasing a sophisticated process understanding, especially concerning the physical effect of arc behavior, which can provide many strategies to enhance weld prediction and joint quality. In this article, the arc behaviors studied by its arc pressure, static characteristic, and arc profile in terms of arc force are presented. With the help of the forces acting on the welding arc, arc profile can be considered separately to allow an improved investigation of narrow gap welding involved. Measurements of arc pressure distribution are used to validate the weld formation and the final welding result. Under the same conditions, the uniformity of arc pressure distribution in both the bottom and sidewall improved with the increase in magnetic flux density. Furthermore, a comparative study of arc static characteristic with magnetic field and non-magnetic field has also been carried out. The reduction in the difference of arc static characteristic is attributed to the inverse effect between electromagnetic pinch force and Lorentz force with the increasing welding current.

Optimization of magnetic arc oscillation system by using double magnetic pole to TIG narrow gap welding

A magnetic arc oscillation system for tungsten inert gas (TIG) narrow gap welding is developed to prevent insufficient sidewall fusion and improve efficiency and quality for thick component welding. The characteristic of the system is that a double magnetic pole is induced by exciting current flowing through the field coil to generate the magnetic field within the welding area. This optimization of double magnetic pole not only enhances magnetic flux density compared with conventional single magnetic pole but also provides reliable melting of the sidewall. In this article, a new experimental method for the determination of the resulting heat input into the workpiece is proposed. Measurements of arc voltage and welding current flowing through the sidewalls are used to validate the redistribution of the arc heat. Furthermore, the difference of linear heat input of the sidewalls caused by current division ratio difference and arc voltage difference was the main reason why the formation characteristics occurred.

Effect of Pulsed TIG Welding Parameters on the Microstructure and Micro-Hardness of AA6061 Joints

Tungsten Inert Gas (TIG) welding process is generally used for welding of aluminum alloys. TIG process is generally preferred because it produces a very high quality weld. Distortion is the major problem in welding of thin sections. This distortion is controlled in pulsed and magnetic arc oscillation TIG process. The metallurgical advantages of pulsed TIG welding are grain refinement in fusion zone, reduced width of HAZ, less distortion, control of segregation, reduced hot sensitivity and residual stresses. It was observed that pulsed TIG welding produces finer grain structure of weld metal than conventional TIG welding (without arc pulsation). The mechanical properties (Hardness) and microstructure characteristic of weld metal depends upon the microstructure of the weld. The microstructure of the weld depends upon pulsed parameters peck current, base current, pulse frequency, pulse duration. The objective of present project is to achieve better mechanical properties. So, controlling of pulsed parameter is needed in this investigation. An increase in the pulse frequency has been found to refine the grain structure of weld metal especially when welding is done using short pulse duration. Long pulse duration lowers the pulse frequency up to which refinement of constituents in weld metal takes place. Effect of the pulse frequency on the grain structure was found to be determined by pulse duration. For a given pulse frequency, long pulse duration produced a coarser structure than short pulse duration. An increase in the peak current coarsened the grain structure.

Reducing hot cracking tendency of dissimilar weld overlay by magnetic arc oscillation

Nickel filler metals are used for joining and repair of dissimilar metal welds in nuclear power plants. However, with some compositions of austenitic stainless steel base metals, weld cracking is observed. In the present work, the solidification cracking behaviour of 52M overlay on stainless steel with and without magnetic stirring was studied. Single, double and triple bead on plate experiments with 52M filler wire were performed on a type 303 stainless steel plate cladding with a single layer of ER308LSi stainless steel. Weldings were then performed with and without magnetic stirring. Although cracking tendency was observed in all experiments, it was seen that magnetic stirring significantly reduced the cracking tendency. Confirmatory electron backscattered diffraction analyses confirmed the grain refinement in 52M beads with magnetic stirring.

The Effect of Ultrasonic Vibration on Properties of Weld Metal

Weld metal mechanical properties and weldability of materials are closely related to the microstructure of the weld metal. A significant amount of research has been studied to improve microstructure of weldments such as weld pool stirring by using magnetic arc oscillation and arc pulsation. In this work, the effect of ultrasonic vibration was used to modify weld metal solidification to improve microstructure of the weld metal. Microstructure and mechanical properties of carbon steel weld metal (ER70S-G filler metal) were studied. Filler metal was melted by using Gas Tungsten Arc Welding (GTAW) in a water-cooled copper mold. Ultrasonic vibration with a frequency of 20 kHz was applied during solidification of the weld metal. Microstructure and mechanical properties of weld metal were compared with those of conventional weld metal (no ultrasonic vibration assistance). Scanning Electron Microscopy (SEM) was also used to determine microstructure and phases at high magnification. The results showed that ultrasonic vibration applied during solidification promoted grain refinement in the weld metal. Mechanical properties of weld metal were improved significantly, microstructure analysis correlated well with the mechanical test results.

Optimization of magnetic arc oscillation process parameters on mechanical properties of AA 5456 Aluminum alloy weldments

The present work pertains to the improvement of mechanical properties of AA 5456 Aluminum alloy welds through magnetic arc oscillation process. Taguchi method was employed to optimize the magnetic arc oscillation welding process parameters of non-heat treatable AA 5456 Aluminum alloy welds for increasing the mechanical properties. The same optimum condition was observed in all the properties. Regression models were developed. The effect of welding current, welding speed, amplitude and frequency on mechanical properties was also studied. Analysis of variance was employed to check the adequacy of the developed models. Microstructures of all the welds were studied and correlated with the mechanical properties.