Explore the vast range of titles available.

As a result of the thermo-mechanical impact during welding, distortions are generated in welded structures. These distortions significantly influence the geometric and dimensional accuracy of welded structures, in many cases lowering their working characteristics and reliability. An optimal design for welded structures is a prerequisite for increased reliability and reduction in manufacturing cost, and such an optimal design can be achieved knowing the distortions in weldments. Despite the fact that pulsed metal inert gas welding and metal active gas welding have been broadly applied in the last few decades, nowadays, few manufacturers, for instance, Fronius, EWM, Redco, and Perfect Power Welders, offer such an option for manual arc welding. This work aims to determine the influence of the parameters of pulsed welding modes on distortions that are generated during manual arc welding. Two different inverter welding power sources were used, and the welding distortions were measured by 3D scanning. The results showed that the pulsed mode during manual arc welding led to a reduction in distortions compared to the conventional welding mode. The crucial part of the manual welding system proved to be the qualification and performance of the welder.

Wire arc additive manufacturing (WAAM) is a crucial technique in the fabrication of 3D metallic structures. It is increasingly being used worldwide to reduce costs and time. Generally, AM technology is used to overcome the limitations of traditional subtractive manufacturing (SM) for fabricating large-scale components with lower buy-to-fly ratios. There are three heat sources commonly used in WAAM: metal inert gas welding (MIG), tungsten inert gas welding (TIG), and plasma arc welding (PAW). MIG is easier and more convenient than TIG and PAW because it uses a continuous wire spool with the welding torch. Unlike MIG, tungsten inert gas welding (TIG) and plasma arc welding (PAW) need an external wire feed machine to supply the additive materials. WAAM is gaining popularity in the fabrication of 3D metal components, but the process is hard to control due to its inherent residual stress and distortion, which are generated by the high thermal input from its heat sources. Distortion and residual stress are always a challenge for WAAM because they can affect the component’s geometric accuracy and drastically degrade the mechanical properties of the components. In this paper, wire-based and wire arc technology processes for 3D metal printing, including their advantages and limitations are reviewed. The optimization parametric study and modification of WAAM to reduce both residual stress and distortion are tabulated, summarized, and discussed.

The manufacturing industry plays a vital role in the economic foundation of many countries. To meet increasing demands, operational efficiency and product quality must be closely monitored. These are commonly measured using Key Performance Indicators, including Overall Equipment Effectiveness, which is based on availability, performance, and quality. Manual OEE measurement often leads to delays, inaccuracies, and limited real-time monitoring. To address these challenges, this research proposes an automated, real-time OEE Calculation System (OEE-CS) for Metal Inert Gas welding machines using Industry 4.0 technologies such as the Internet of Things and Cyber-Physical Systems. Data from sensors is transmitted wirelessly, analyzed, and displayed through a user-friendly interface accessible via smartphone or PC. Experimental results show that the OEE-CS accurately calculates OEE components with an average deviation of 4.5% compared to manual methods. The system also correctly identifies non-operational periods, yielding an OEE value of 0% when no production is scheduled. These findings demonstrate the system’s reliability and its potential to support data-driven decision-making in real time.

This study compared the microstructure and mechanical characteristics of AA6061-T6 joints produced using friction stir welding (FSW), friction stir vibration welding (FSVW), and tungsten inert gas welding (TIG). FSVW is a modified version of FSW wherein the joining specimens are vibrated normal to the welding line during FSW. The results indicated that the weld region grains for FSVW and FSW were equiaxed and were smaller than the grains for TIG. In addition, the weld region grains for FSVW were finer compared with those for FSW. Results also showed that the strength, hardness, and toughness values of the joints produced by FSVW were higher than those of the other joints produced by FSW and TIG. The vibration during FSW enhanced dynamic recrystallization, which led to the development of finer grains. The weld efficiency of FSVW was approximately 81%, whereas those of FSW and TIG were approximately 74% and 67%, respectively.

High-entropy alloys (HEAs) have been proven to exhibit superior structural properties from cryogenic to high temperatures, demonstrating their structural stability against the formation of complex intermetallic phases or compounds as major fractions. These characteristics can find applications in nuclear and aerospace sectors as structural materials. As the dissimilar joint design is necessary for such applications, an attempt is made to fabricate the dissimilar transition joint between Al0.1CoCrFeNi-HEA and AISI304 austenitic stainless steel by conventional tungsten inert gas welding. Microstructural characterization by SEM and EBSD clearly revealed the evolution of columnar dendritic structures from the interfaces and their transformation to equiaxed dendritic grains as they reach the weld center. Also, considerable grain coarsening was observed in the heat-affected zone of the HEA. The tensile test results depict that the dissimilar weld joint showed significantly higher tensile strength (590 MPa) than the HEA (327 MPa), making it suitable for structural applications.

In recent years, the demand for advanced high-strength steel (AHSS) has increased to improve the durability and service life of steel structures. The development of these steels involves innovative processing technologies and steel alloy design concepts. Joining these steels is predominantly conducted by following fusion welding techniques, such as gas metal arc welding, tungsten inert gas welding, and laser welding. These fusion welding techniques often lead to a loss of mechanical properties due to the weld thermal cycles in the heat-affected zone (HAZ) and the deposited filler wire chemistry. This review paper elucidates the current studies on the state-of-the-art of weldability on AHSS, with ultimate strength levels above 800 MPa. The effects of alloy designs on the HAZ softening, microstructure evolution, and the mechanical properties of the weld joints corresponding to different welding techniques and filler wire chemistry are discussed. More specifically, the fusion welding techniques used for the welding of AHSS were summarized. This review article gives an insight into the issues while selecting a particular fusion welding technique for the welding of AHSS.

The amount of metal materials is gradually increasing with the rapid development of manufacturing industry. Medium-thick plate aluminum alloy is widely used in heavy military vehicles, marine engineering, and other fields for weight reduction or corrosion resistance. However, it is difficult to obtain high-quality deep penetration welds by traditional welding technology to meet the requirements. Based on the welding solution of plate aluminum alloy, this paper summarizes the deep penetration welding process of aluminum alloy plates and analyzes the mechanism and research progress of various process methods. It mainly includes active flux tungsten inert gas welding, pulse melting electrode inert gas welding, swing arc narrow gap GMAW welding, high energy beam welding and laser arc hybrid welding, etc. The welding technology assisted by external magnetic field or ultrasonic field can also realize deep penetration of the weld, and can improve the weld forming, reduce porosity and cracks and other defects. The research on deep penetration welding technology is helpful to promote the high-speed development of plate aluminum alloy welding to automation and intelligence.

Welding techniques are widely utilized for permanent material joining. The tungsten inert gas (TIG) welding process is notable for its exceptional precision, controlled heat input, and affordable equipment. It is widely employed for joining different grades of steel. Currently, extensive research is being conducted to enhance the quality of welded joints. This involves exploring various welding methods and adjusting welding parameters to improve characteristics such as strength, ductility, formability, appearance, and corrosion resistance. The current investigation’s main aim consists of studying the effect of the welding parameters, i.e., the welding current and the gas flow rate, on the mechanical properties of welded joints of low-carbon steel with a thickness of 1 mm. The yield strength, tensile strength, and strain at break are selected as responses. The analysis of variance (ANOVA) is utilized to check the impact of welding parameters on the responses, while the Gray Relational Analysis (GRA) is used to optimize the welding parameters to maximize the chosen responses. Results show that welding current possesses the most influence on the three responses, i.e., the yield strength, tensile strength, and strain at break. The combination of 65 A welding current and 15 l/min gas flow rate allows the maximization of the three responses.

A lightweight, highly corrosive resistant, and high-strength wrought alloy in the aluminum family is the Aluminium 8006 alloy. The AA8006 alloy can be formed, welded, and adhesively bonded. However, the recommended welding methods such as laser, TIG (Tungsten Inert Gas welding), and ultrasonic are more costly. This investigation aims to reduce the cost of welding without compromising joint quality by means of friction stir welding. The aluminum alloy-friendly reinforcement agent zirconia is utilized as particles during the weld to improve the performance of the newly identified material AA8006 alloy in friction stir welding (FSW). The objectives of this research are to identify the level of process parameters for the friction stir welding of AA8006 to reduce the variability by the trial-and-error experimental method, thereby reducing the number of samples needing to be characterized to optimize the process parameters. To enhance the quality of the weld, the friction stir processing concept will be adapted with zirconia reinforcement during welding. The friction stir-processed samples were investigated regarding their mechanical properties such as tensile strength and Vickers microhardness. The welded samples were included in the corrosion testing to ensure that no foreign corrosive elements were included during the welding. The quality of the weld was investigated in terms of its surface morphology, including aspects such as the dispersion of reinforced particles on the welded area, the incorporation of foreign elements during the weld, micro defects or damage, and other notable changes through scanning electron microscopy analysis. The process of 3D profilometry was employed to perform optical microscopy investigation on the specimens inspected to ensure their surface quality and finish. Based on the outcomes, the optimal process parameters are suggested. Future directions for further investigation are highlighted.

Welding is one of the key joining routes for expanding the engineering applications of dissimilar magnesium alloys. However, after experiencing rapid non-equilibrium heating and cooling cycles, the heat-affected zone (HAZ) of a welded joint tends to undergo grain coarsening as well as dissolution or agglomeration of precipitates, and therefore becomes the region most susceptible to failure. In this study, 3 mm thick sheets machined from AZ61A and AZ80A magnesium alloy hollow sections were joined by metal inert gas welding (MIG). Different ranges of welding heat input were obtained by combining multiple sets of welding parameters, in order to further tailor the HAZ of dissimilar magnesium alloy joints and achieve sound weld quality. The results showed that the joint exhibited the best overall mechanical performance at 523 J·mm−1, with an ultimate tensile strength, yield strength, and elongation of 292 MPa, 172 MPa, and 5.4%, respectively. All fractures occurred in the HAZ on the AZ61A side. Under this condition, the second phases in the HAZ were more finely and uniformly dispersed, with a volume fraction of 3.19%, an average size of 2.51 μm, and a minimum average grain size of 23.65 μm.