Traditional Welding Methods Research Articles

Intelligent Design of Robotic Welding Process Parameters Using Learning-Based Methods

With the wide application of multi-layer and multi-pass welding in industry, the traditional manual welding method is difficult to meet the needs of manufacture. Welding Robot has the advantages of stable productivity, ensuring welding quality even in special environment, so the welding robots are used at a growing trend in manufacturing fields to complete different welding tasks. In this paper, an intelligence learning method for welding robot is designed, aiming at the prediction of welding process parameters and bead geometry parameters in the welding process, deep and machine learning algorithms are used for realization. It provides an instruction for the design of process parameters to realize the intellectualization and automation of welding robot. The experimental results show that automatic parameters learning based on machine learning are effective and different learning methods should be selected for different process parameter prediction tasks in order to achieve the best prediction effect.

A review study in ultrasonic-welding of similar and dissimilar thermoplastic polymers and its composites

Due to the use of integrated materials in aerospace, automotive, sportswear, wind turbine and other fields, the industry is demanding new technologies and is rapidly adapting to more complex composite structures. In the last several years, unlike traditional welding methods, ultrasonic joining has become an important relevance in many applications areas. The random distribution and poor mechanical characteristics of grain always make it difficult to connect dissimilar materialsin the conventional welding process. The Ultrasonic-Welding technology for joining thermoplastic (TP) compounds is fast and energy efficient. Compared to other joining processes (adhesive, mechanical etc.), this welding method is more economical. This review's key features are the Ultrasonic-Welding process, theory, advantages, and limitations, process parameter, the effect of Energy director (EDs), Ultrasonic-Welding (UW) of similar and dissimilar TP composites and TP. The present state of UW and future viewpoints of TP composites are also explored.

Exploring potential benefits of additive manufacturing in creating corrugated web steel beams

This research aims at exploring the potential benefits of additive manufacturing of corrugated web steel beam structural systems. Various three-dimensional models of corrugated web beams were created, manufactured, then analyzed by the finite element method. Four prototypes were manufactured using the traditional welding method, one regular, and three are corrugated web beams. Three other prototypes of corrugated web beams, similar to the previously traditionally manufactured, were created using additive manufacturing. Experimental tests were conducted on these prototypes. Both the finite element analysis and the experimental study showed that the additively manufactured beams having higher load carrying capacity when compared to traditionally manufactured ones. Also, the additively manufactured corrugated web beams performed very closely to the finite element analysis showing a high level of certainty making it possible to reduce the safety factors thus reducing the total costs. The results show that additive manufacturing technology can effectively be employed for creating structural systems without limitations and without causing any errors in the manufacturing process.

Effects of Ar-He shielding gas mixture on mechanical and metallurgical properties of weld metal in laser welding of 6061 T6 aluminium alloy

In this study, a 6 mm-thick 6061 T6 aluminum alloy was welded using fiber laser welding, and its mechanical and metallurgical properties were investigated. Full penetration autogenous welds were made at a constant laser power of 4.95 kW using a continuous-wave fiber laser and focal positions of −4 mm. In addition, the shielding gas content was changed for weldments welded at different travel speeds (mm s−1). Accordingly, welding speeds were 50, 40, 35, 25, and 20 mm s−1, and the shielding gas contents were 100% argon (Ar), 10% helium (He) + 90% Ar, 30% He + 70% Ar, 50% He + 50% Ar, and 75% He + 25% Ar. Then, macro and micro images were taken, and some mechanical properties (hardness, tensile test, and bending test) were examined. As a result, the change in shielding gas content and welding speed has provided significant variations in the welding joints. Decreases in mechanical properties were detected due to the coarsening of the precipitates. On the other hand, the narrowness of the weld seam and HAZ obtained in laser welding, compared to traditional welding methods, minimizes this disadvantage.

Analysis of Autogenous Laser Welding in Low Carbon and Large Thickness Steel

With the use of laser welding, it is possible to join different steel, with different thicknesses, with or without the action of protective layers. The quality of laser radiation makes it possible to get certain characteristics that are impossible to get by other processes, such as high welding speeds, less metallurgical effects suffered by the heat-affected zone (ZAC), and this process also does not require filler metal, therefore it is free from possible contamination. Combined with traditional welding methods, laser welding produces narrower weld beads, allowing for better prevention of corrosion and thermal distortions. Although the process already has high industrial knowledge, some random defects, such as porosities and inconsistencies, are still found. This work presents a systematic study to determine the influence of laser welding parameters and how these parameters influence welding defects. For this, the experimental part was carried out in the welding laboratory - LABSOLDA, of the Federal University of Santa Catarina - UFSC, during the laser welding processes, a welding speed of 2.4 m/min was reached. For this experiment, argon was used as a shielding gas and 1020 steel was used as the base material.

전기자동차 알루미늄 이종소재의 하이브리드 Clinching 접합특성에 따른 기계적 특성

Recently, in the automobile industry, the development of technology that can satisfy environmental regulations and fuel economy reduction requirements due to vehicle weight is an important topic. To solve this issue, vehicle-body weight reduction technology is a promising solution. To reduce the vehicle weight, automobiles with a large amount of aluminum use general wire welding (MIG, TIG) to bond aluminum components to each other. However, for complex three-dimensional shapes and dissimilar materials, traditional welding methods of inducing metal bonding and joining access are difficult to implement. Therefore, in such cases, joining techniques should be used. In this study, the mechanical properties of clinching joints without rivets are studied among various mechanical joint methods for weight reduction.

Nove tehnologije montaže brodskog trupa u brodogradnji

The modern stage of shipbuilding industry development is characterized by an intense competition and the beginning of introduction of new materials and effective welding technologies, which change the appearance of this quite conservative field, at leading global shipbuilding enterprises. In particular, the application of laser technologies during ship construction decreases the cost of hull manufacturing by 30%, increases the production capacity by 10%, and reduces welding deformations by 30% compared to traditional welding methods. The application of composite materials for ship construction allows decreasing the ship weight by 10%, which leads to 1-7% decrease in fuel consumption, reduction of polluting emissions and significant saving of expenditures. Adhesion-bonded joints become more frequently used in shipbuilding, as they off er a possibility of joining different materials along with the advantages brought by the adhesion process itself, being reliable, cost-efficient and ensuring easy maintenance and repair.

Friction Stir Welded AISI 304 Metal Sheets for Application in Food Implants

Stainless steels are indispensable materials in many industrial fields. They can be easily shaped and joined by traditional welding methods. Some problematics such as possible decrease in corrosion resistance at the welding bead and in the heat-effected zone, residual stress, crack formation and distortions may take place after welding. Friction Stir Welding (FSW) may be used for joining stainless steels in a single pass and for optimising microstructure and mechanical properties of the processed region. The application of FSW to the widely used AISI304 stainless steel is investigated in food implants. The mechanical properties together with corrosion resistance and surface finishing are characterized. A high energy input is chosen for the welding (2000 rpm tool rotational speed and 50 mm/min advancing speed). The stirred zone (SZ) is characterized by optical microscopy. Vickers microhardness in the SZ results 37% higher than in the base material. Tensile tests highlight elongations up to 40% keeping maximum stress values at 600 MPa. All samples pass accelerated corrosion tests that simulate 20 years of cleaning cycles in a typical food implant.

A Analysis the influence of threaded pin profiles in friction stir welding by numerical simulation

Currently, the welding industry has made significant contributions in most production fields to meet the needs of people's lives. However, traditional welding methods have disadvantages such as: a large amount of energy consumption, production of many toxic gases that are harmful to the environment and the health of workers. Therefore, the friction stir welding method was introduced from the research of scientists to overcome the above disadvantages. Besides that, it is suitable for welding aluminum alloys and non-ferrous metals with low melting point. This green welding technology has been continuously researched to improve weld quality through two main research models: experiment models and numerical simulation models. Experimental results provide provides the basic mechanical properties of the materials at the weld and the process optimization parameters. It will be the basis to establish a numerical simulation model closest to reality, based on mathematical models and working principles, thereby helping to predict weld quality through prediction of formation defects, temperature distribution with changes in welding process parameters such as time, velocity, material or welding pin profile. In this study, the influence of threaded pin profiles on weld quality of alloy aluminum 7075 -T6 during friction stir welding was investigated by numerical simulation model through ABAQUS software to recommend a new pin profile bringing an efficient welding process. To increase the reliability of this research approach, the numerical simulation results of the temperature distribution are compared with the experimental results obtained from a foreign scientific paper with an average error of 14%. Threaded pin profiles are designed in combination with three cross-sections having different opening angles named TF0, TF30, TF60 and TF90. Coupled Eulerian-Lagrangian formulation is applied for this model where the welding tool is Lagrangian domain and workpiece is Eulerian domain. Because material deformation in friction stir welding process is large and related to temperature, the elastic-plastic Johnson-Cook model is used for workpiece. Results of this research shows a new pin profile named TF60 which it gives the best weld quality of the four configurations of the pin tool examined in this study through evaluating temperature distribution and predicting weld defect formation.

Investigations on GTAW and FSW of Al6061-ZrB2-Fly ash hybrid metal matrix composites

Various hard ceramic particles, carbonaceous, organic, fibers, and other materials are used to reinforce aluminum alloys. These composites, identified as aluminum metal matrix composites possess low density, high strength, low thermal expansion, and strong structural rigidity. In this research work, a comparison of the traditional fusion welding method (GTAW) and Friction Stir Welding (FSW) in joining such composites is carried out. Suitable parameters for the welding process are estimated to join Al6061-ZrB2-fly ash composites. The mechanical or physical properties of the parent metal and weldments, such as tensile strength and hardness, are investigated. In addition, their microstructure correlations are also evaluated. It is found that the physical properties of the parent metal have improved as a result of the variations in the reinforcements. At the higher percentage of the reinforcement, the properties have deteriorated due to the excess slag accumulation. The fusion welding process yielded better mechanical properties than the solid-state welding system in the comparative analysis. This is attributed to the efficiency of the fusion welding process for joining composites of this kind. Despite the fact that the solid-state welding process produced better microstructures in the weld region, particle segregation occurred, lowering the properties. Unlike other studies, the microstructure of the fusion-welded samples here has greater integrity and less particle segregation. Grain refining has also occurred, resulting in improved mechanical properties.

Optimisation of friction stir welding parameters using combined Taguchi L9 and genetic algorithm

'Friction stir welding' (FSW) is an eco-friendly, energy-efficient solid-state welding procedure invented for high strength alloys as well as materials that are otherwise difficult for welding through the traditional fusion welding methods. This research paper elaborates on a hybrid Taguchi-genetic algorithm that optimises the FSW process parameters to yield favourable electrical conductivity of aluminium alloy AA1350. The optimisation parameters considered are travel speed, rotational speed and tool tilt angle. First, the Taguchi method is applied to reduce the number of design experiments and find the optimal set for quality parameters of the system. Subsequently, the genetic algorithm is employed to search for the optimum set of design parameters by using Taguchi solution as the initial population. The results obtained by the proposed method were compared to the outcomes of the conventional Taguchi L9 method and the simple genetic algorithm. The best performance was obtained by the proposed method in 51 iterations, whereas simple genetic algorithm used 182 iterations for the same.

Optimisation of friction stir welding parameters using combined Taguchi L9 and genetic algorithm

'Friction stir welding' (FSW) is an eco-friendly, energy-efficient solid-state welding procedure invented for high strength alloys as well as materials that are otherwise difficult for welding through the traditional fusion welding methods. This research paper elaborates on a hybrid Taguchi-genetic algorithm that optimises the FSW process parameters to yield favourable electrical conductivity of aluminium alloy AA1350. The optimisation parameters considered are travel speed, rotational speed and tool tilt angle. First, the Taguchi method is applied to reduce the number of design experiments and find the optimal set for quality parameters of the system. Subsequently, the genetic algorithm is employed to search for the optimum set of design parameters by using Taguchi solution as the initial population. The results obtained by the proposed method were compared to the outcomes of the conventional Taguchi L9 method and the simple genetic algorithm. The best performance was obtained by the proposed method in 51 iterations, whereas simple genetic algorithm used 182 iterations for the same.

Research on Interface Characteristics and Mechanical Properties of 6061 Al Alloy and Q235a Steel by Hot Melt-Explosive Compression Bonding

In order to solve the shortcomings of the traditional explosion welding method for direct magnesia-aluminum alloy and steel welding, a processing method of groove hot casting plus explosion compression bonding (HCECB) was put forward, and the related theory of hot-melt metal plus explosion bonding was also proposed. Taking 6061 aluminum and Q235a steel as examples, the hot casting plus explosion compression test was carried out by the prefabrication of a dovetail groove on Q235a steel plate and the microstructure and mechanical properties of the interface were analyzed. The results showed that the 6061 aluminum/Q235a steel can be directly combined by the HCECB method. The interface is mainly irregularly microwave-shaped and straight-shaped with no defects, such as melting layer, holes and cracks, found. The hardness of the upper interface of the dovetail groove is larger than that far away from the welding interface, while the hardness of the lower interface is the same as that far away from the interface. The tensile and shear test results show that the shear strength is greater than 80 MPa, which meets the requirements of aluminum-steel composite plate bonding strength.

Research progress of aluminum alloy welding technology

With the development of aerospace, marine engineering, and other industries, aluminum alloys are widely used. There are welding defects in the traditional welding method for welding aluminum alloys. This article discusses an advanced method based on traditional welding methods, which can effectively reduce the probability of defect occurrence. In these methods, welding with an external magnetic field can promote the formation of equiaxed crystals during crystallization, grain refinement, and improved weld performance. The porosity is reduced and the sensitivity to thermal cracking is reduced. The future development direction of aluminum alloy welding is discussed at the end of the article.

Exploration of mechanical and metallurgical characterization of Incoloy 20 weldment using gas tungsten arc welding methods

In this paper, metallurgical and mechanical properties are assessed for Incoloy 20 weldment made using traditional arc welding methods with ERNiCrMo-4 filler metal. High magnification microscopes (optical and scanning electron microscopes) are utilized to observe the microstructure of welded specimens. Energy dispersive X-ray spectroscopy is utilized to explore the elemental segregation of welded specimens. Secondary precipitates formed during welding are identified through X-ray diffraction method. It is explored that crack-free weldments are achieved from both continuous current gas tungsten arc welding (CCGTAW) and pulsed current gas tungsten arc welding (PCGTAW) processes. Hardness, impact and tensile tests are conducted to identify the mechanical properties for welded specimens. Results of CCGTAW and PCGTAW specimens are compared and analyzed in detail. Comparatively, PCGTAW specimens offered better results than that of CCGTAW.

Mechanical Properties of AW-5083 Alloy Joints Welded By Hybrid Method – FSW and MIG

Abstract The article presents the research results on the mechanical properties of aluminum alloy AW-5083 and its joints welded by hybrid method – traditional MIG and FSW. AW-5083 alloy is the most currently used in shipbuilding industry. Friction Stir Welding (FSW) – a new technology can be successfully used for butt-welding of different types of aluminum alloy sheets. FSW method can be an alternative to traditional arc welding methods i.e. MIG or TIG. Hybrid welding (FSW with MIG or TIG) could be used in cases when joining only by FSW is not possible. Welding parameters used for the connection of the sheets were presented. Metallographic analysis showed the correct construction of structural bonded joints. The research was carried out using a static tensile test in accordance with the requirements of the Standard PN-EN ISO 4136:2013-05. Flat samples cut perpendicular to the direction of rolling were used. The research was conducted at the temperature of +20ºC. The test shows that the mechanical properties of joints made by hybrid method compered to native material were lower. The tensile strength of joint was lower by 20% then native material 5083 while its yield stress was lower only about 6%. The biggest change was observed in case of plastic properties. Elongation of joint was over 50% lower compared to native material. Despite the decrease of mechanical properties, they meets the requirements of classification societies, so the conclusion is that hybrid method (FSW and MIG) of joining AW-5083 can be applied in shipbuilding industry.

Microstructure and mechanical properties of friction stir welded dissimilar 5754-H111-6013-T6 aluminum alloy joints

Abstract Aluminum alloys exhibit good strength, excellent corrosion resistance and good forming properties along with low specific density. Due to these superior properties, they are widely used in the automotive, chemical, and food industries, especially in shipbuilding and the yacht industry. It is important to join these alloys used in the mentioned industrial areas. However, it is very difficult to join Al and its alloys via traditional welding methods despite its widespread use. In this study, 5754-H111 and 6013-T6 aluminum alloys were joined by friction stir welding. Welding operations were carried out at 1250 rpm using welding feed rates of 12.5, 25, and 32 mm × min−1. Metallographic investigations were carried out to determine the microstructural and macrostructural properties of the weld zones. Tensile, bending, and hardness tests were also performed to determine the mechanical properties of the welded samples. The results obtained as a result of the tests were evaluated and interpreted. Micro-void defects were found to occur in the weld metal–HAZ transition zones. It was established that the welding speed affected the tensile strength. The highest tensile strength was obtained at a feed rate of 25 mm × min−1. It was determined that no cracking or fraction occurred in the welded samples as a result of the bending test.

Microstructure Evaluation on Friction Stir Welding of Cryorolled 2219 Aluminum Alloy

Abstract This article presents a study of friction stir welding (FSW) on cryorolled (CR) AA2219 alloy using a hexagonal pin tool with different set of process parameters. Normally, AA2219 alloy is difficult to weld, but it is possible to get a defect-free, sound weldment with a solid-state welding technique (FSW) compared to traditional welding methods. Here, among the 9 weld joints, the weld made on CR AA2219 by the hexagonal pin tool with 1,000 r/min tool rotational speed at 25 mm/min welding speed and 3° axis inclination exhibited better tensile strength, impact toughness, hardness, and corrosion resistance. It was confirmed by microscopy analysis that the ultrafine grains structure and dissolution of Al2Cu were present at the weld zone. The fine dimple morphology was found at the fracture surface area of weldment. Also, the X-ray Diffraction (XRD) and energy-dispersive X-ray results showed that the intensity of Al2Cu was decreased at the weld portion for the CR AA2219. Dissolution of precipitates resisted the flow of electrons and delivered good resistance against corrosion. Corroded portion surface topography was analyzed, and pit details were measured.

A STUDY ON THE FACTORS AFFECTING THE FLARE OF THE WELD WHEN WELDING THE STEEL WIRE

In this study, an equation for adjusting the parameters affecting the flare of the weld on the welding product was established. Based on the empirical research results, the factors affecting welding flux after using bending machines have been studied. It has showed that the factors like the press force, the welding mode, the welding current, and the welding time were the main factors afftecting directly the flaration of the weld. For the standard of the flare of the weld of 3.3 mm, the welding current was 22A, the welding time was 5 deci-seconds, and the press force was 2.78 Kg/cm2. The results showed that the automatic steel-wire welding after improving the welding machine and mode had a productivity of 5.8 times higher and reduced 20% of energy consumption compared to traditional welding methods. Compared with unmodified automatic welding, the productivity increased by 5.8%, energy decreased by 7%, and the weld quality was more stable.

PRELIMINARY STUDY ON EFFECT OF ROD GEOMETRY IN FHPP BETWEEN FE55006 NODULAR CAST IRON AND SAE 8620 STELL

Nodular cast irons are an excellent alternative in manufacturing process of axels due to their characteristics and good mechanical properties. However, the necessity of joining the axels to the gears and other components, made in carbon steel, is a great challenge. Traditional fusion welding methods applied to dissimilar ferrous materials are not deeply studied. In this context, it is well known that different materials have distinct melting points which can cause difficulty in welding, besides of defects formation from solidification. Therefore, modern joining processes such as Friction Hydro Pillar Processing (FHPP) are a great alternative. In this technology, a consumable rod is rotated against to a base material, generating the heat due to the friction, promoting materials in the plastic state and then producing the weld. Hence, this work presents a preliminary study of FHPP between the FE55006 nodular cast iron and SAE 8620 steel and evaluates the rod geometry influence on microstructure and surface stresses of the welded joints. Two rod geometries were used and two welds were further produced. The results indicated that an increase in the rod contact area promoted a lower surface stress as well as a better welded joint.