GMAW Research Papers - Academia.edu (original) (raw)

In this paper, a methodology for understanding the relationships between process parameters and the bead area geometry are presented. The objective of the first part of this study is to find the optimal bead area geometry in the Gas Metal Arc Welding (GMAW) process. A radial basis function (RBF) neural network is used for the prediction of the cross sectional area of the welding bead using a three level factorial design of experiments for the training of the neural network.

- by
- •
- Radial Basis Function, Neural Networks, Welding, GMAW
- by Paul Kah
- •
- Mechanics, GMAW

The effects of the hot stamping process and different hardfacing techniques, such as shielded metal arc welding (SMAW) and gas metal arc welding (GMAW), on the abrasive wear of ploughshares were investigated under field operational conditions. The abrasive wear losses were determined by measuring the weight and dimension changes before and after tillage. The wear losses of hot-stamped and hardfaced ploughshares were less significant than those of the conventionally heat-treated ploughshare specimens used under field conditions. Conventional heat treatment and hardfacing by the SMAW process decreased the wear weight losses by 46.31% and the dimensional losses by 86.77% in comparison to the performance of the conventionally heat-treated ploughshares. These values were 36.90% and 88.17%, respectively, for conventional heat treatment and hardfacing by the GMAW process. There were no statistically significant differences between the SMAW and GMAW hardfacing processes in terms of wear los...

- by Aysel YAZICI (Ph.D)
- •
- Wear, Soil and Tillage, GMAW, Hardfacing

The metal 3-D printing market is currently dominated by high-end applications, which make it inaccessible for small and medium enterprises, fab labs, and individual makers who are interested in the ability to prototype and additively manufacture final products in metal. Recent progress led to low-cost open-source metal 3-D printers using a gas metal arc welding (GMAW)-based print head. This reduced the cost of metal 3-D printers into the range of desktop prosumer polymer 3-D printers. Consequent research established good material properties of metal 3-D printed parts with readily-available weld filler wire, reusable substrates, thermal and stress properties, toolpath planning, bead-width control, mechanical properties, and support for overhangs. These previous works showed that GMAW-based metal 3-D printing has a good adhesion between layers and is not porous inside the printed parts, but they did not proceed far enough to demonstrate applications. In this study, the utility of the GMAW approach to 3-D printing is investigated using a low-cost open-source metal 3-D printer and a converted Computer Numerical Control router machine to make useful parts over a range of applications including: fixing an existing part by adding a 3-D metal feature, creating a product using the substrate as part of the component, 3-D printing in high resolution of useful objects, near net objects, and making an integrated product using a combination of steel and polymer 3-D printing. The results show that GMAW-based 3-D printing is capable of distributed manufacturing of useful products for a wide variety of applications for sustainable development.

- by Joshua Pearce and +1
- •
- Engineering, Materials Science, Design, Digital Fabrication

Final year project report

- by ahmad amir
- •
- Welding Engineering, Welding and Joining, Welding, GMAW

The relationship between microstructure and properties is not widely assessed in parts produced by additive manufacturing, particularly for aluminum. These relationships can be used by engineers to develop new materials, additive processes, and additively manufactured parts for a variety of applications. Thus, the tensile, compressive, and microstructural properties of common aluminum weld filler alloys (ER1100, ER4043, ER4943, ER4047, and ER5356) were evaluated following gas metal arc weld (GMAW)-based metal 3-D printing to identify optimal alloy systems for this type of additive manufacturing. The porosities in all test specimens were found to be less than 2%, with interdendritic shrinkage in 4000 series alloys vs. intergranular shrinkage in 5356. The 4000 series alloys performed better than 1100 and 5356 with respect to printed bead width, porosity, strength, and defect sensitivity. In comparison to standard wrought and weld alloys, the 3-D printed specimens exhibited similar or superior mechanical properties with only minor exceptions. Long print times allow for stress relieving and annealing that improved the print properties of the 4000 series and 5356 alloys. Overall the GMAW-based 3-D parts printed from aluminum alloys exhibited similar mechanical properties to those fabricated using more conventional processing techniques.

- by Joshua Pearce
- •
- Engineering, Materials Engineering, Mechanical Engineering, Materials Science

This study provides an in-depth investigation into low-cost and no-cost substrate release mechanisms that allow gas metal arc weld 3-D printed ER4043 aluminum and ER70S-6 steel parts to be removed from a reusable print substrate with minimal energy. Aluminum oxide, boron nitride, and titanium nitride coatings were evaluated as possible substrate release agents for aluminum printing. Additionally, the in situ formation of substrate release agents such as intermetallics and oxides were tested for both aluminum and steel printing. Testing was performed with a modified Charpy impact tester to remove 3-D printed metal parts from an 1100 aluminum or A36 low carbon steel print substrate to assess the impact energy required for removal. Specimen porosity was measured prior to sectioning and microstructural analysis, hardness traverses were measured across the specimens, and the elastic and shear moduli of the parts were analyzed via ultrasonic methods. All of the employed substrate release mechanisms minimized weld penetration and, in some instances, formed a brittle phase with the print substrate that allowed the specimens to be removed with minimal impact energy. These results thus provide methods with the removal of metal 3-D printed parts from print substrates with no specialized tooling or equipment conducive to distributed manufacturing.

- by Joshua Pearce
- •
- Recycling, Metallurgy, Intermetallics, 3D printing

Lowcost gas metal arc welding (GMAW)based 3D printing has proven effective at additive manufacturing steel and aluminum parts. Early success, however, was based on handwriting Gcode, which is inadequate for the majority of potential users. To enable automated slicing a 3D model and generating Gcode for an acceptable path for GMAW 3D printing, this paper reports on upgrading of the free and open source CuraEngine. The new slicer, MOSTMetalCura, provides the following novel abilities necessary for GMAW 3D printing: i) change the perimeter metric from width to track count, ii) avoid movement that overlaps previous weld beads, iii) have infill start immediately after the perimeter finished and in the direction that eliminates translations, iv) add a variable pause between layers to allow for substrate cooling, v) configure GPIO pins to turn on/off the welder, and vi) set optimized wire feed speed and voltage of the welder based on printing speed, layer height, filament diameter, and tool track width. The process for initiating these changes are detailed and the new slicer is used to help improve the function of the printer for ER70S6 steel. To find the printing function with the smallest bead width based on volume of material, the line width, layer height, and printing speed are varied to provide wire feed speed calculated by MOSTMetalCura, then the settings are used to print 3D models. The results of 3D printing three case study objects of increasing geometric complexity using the process methodology improvements presented, which show resolution of 1mm bead widths.

- by Joshua Pearce and +1
- •
- Materials Science, Open Source Software, Welding Technology, Welding Engineering

In this study AISI 304 L type of austenitic stainless steels were welded using 308 L consumable electrodes by the process of Gas Metal Arc Welding (GMAW). The aim of current study is to examine effects of shielding gas compositions on mechanical properties and microstructure of AISI 304 L weldments. A detailed study of gas metal arc welding of AISI 304 L stainless steel was carried out with different shielding gas compositions such as 100% argon, 80% argon + 20% CO 2 , 50% Argon + 50% argon and 100% CO 2 . The mechanical properties were determined by performing different tests, viz. Charpy V notch impact test, tensile test, hardness test, bend test. Surface morphology had been analyzed by Scanning Electron Microscope (SEM). The results indicated that the shielding gas compositions have great influence on mechanical properties. Results revealed that increase in amount of CO 2 in shielding gas resulted in higher tensile strength and hardness values than the base metal. The study also indicated that shielding gas composition also have an influence on toughness values which further depends upon -ferrite content in the weld metal. This -ferrite content decreases with increase in CO 2 percentage of shielding gases. Decrease in -ferrite content has negative effects on toughness values of weldments. The gas metal arc welding is found to be suitable for welding of AISI 304 L austenitic stainless steels owing to their high welding speed and excellent mechanical properties.

- by Lourival Santos
- •
- Mechanical properties, GMAW

Alloy development can simplify low-cost gas metal arc weld (GMAW)-based 3-D printing by making it easier to print quality parts with minimal metallurgical or welding experience. Previous work found good properties in aluminum alloys, particularly in the aluminum-silicon 4943 (Al-5.5%Si-0.4%Mg) and 4047 (Al-11.6%Si) alloys. These alloys were easy to print, but could benefit from alloying to increase ductility and to minimize or redistribute porosity. The purpose of this study was to modify 4943 and 4047 alloys and rapidly screen their performance for use as feedstock for improved 3-D printability. The 4047 and 4943-based alloys were modified with additions of magnesium, strontium, titanium boride, and combinations thereof. Wedge-shaped castings were used to efficiently screen alloying additions over the same ranges of solidification rates as those observed in GMAW-based 3-D printing. The alloying additions were most effective at modifying the high-silicon 4047 alloy whereas no change in microstructure was observed in the low-silicon 4943 alloy. Strontium was an effective modifier of the high-silicon alloy. Titanium boride was not observed to have a grain refining effect on aluminum dendrites on its own, although the combination of strontium and titanium boride produced the most refined eutectic structure in the high-silicon alloy. Future work should evaluate the singular effects of strontium, titanium boride, and the combination of strontium and titanium boride additions in weld-based 3-D printing.

- by Joshua Pearce
- •
- Welding Technology, Welding Engineering, 3D printing, Additive Manufacturing

How is welding done? Welding is a fabrication process that joins materials, usually metals or thermoplastics, by using high heat to melt the parts together and allowing them to cool, causing fusion. Welding is distinct from lower... more

How is welding done?
Welding is a fabrication process that joins materials, usually metals or thermoplastics, by using high heat to melt the parts together and allowing them to cool, causing fusion. Welding is distinct from lower temperature metal-joining techniques such as brazing and soldering, which do not melt the base metal.

- by vash leng
- •
- Welding Technology, Steel Structure, Welding and Joining, Friction Welding

El presente articulo describe el desarrollo de un metodo experimental empleado para construir las curvas de Corriente de Soldadura Vs. Velocidad de Alimentacion de Alambre en proceso GMAW, con dos extensiones de electrodo en un modo de transferencia por corto circuito, utilizando un electrodo ER70S-6 y un gas 98%Ar-2%CO2. Se encontro que, manteniendo el voltaje constante, la corriente de soldadura se incremento de manera proporcional (aproximadamente lineal) a la velocidad de alimentacion de alambre e inversamente proporcional a la extension del electrodo. Se compararon las curvas construidas con las disponibles en la literatura y se encontro un desfase de aproximadamente 20 A respecto a la curva resultante para una distancia tubo de contacto-trabajo de 15 mm. Se determino indirectamente la extension del electrodo a partir de la estimacion de las longitudes de arco fotografiadas durante los ensayos.

- by Santiago Aristizábal
- •
- Modeling, Regression Analysis, GMAW, Weld

The purpose of this work was to study the mechanical properties of GMAW welded IRSM41 material based on the grain flow directions. It is a joining process that fuses the base metal to make the weld. The results were analyzed by means of the mechanical properties such as tensile strength, bend test, microstructure and hardness was carried out for both along and across the grain flow direction of the weldments. The important implication about grain flow is that some mechanical properties vary with respect to orientation of the grain flow. The strength and hardness are primarily varied based on the grain flow direction. The desirable properties associated with retarding crack propagation can see significant differences depending on the grain flow and the direction of the moving crack. So, properties like fatigue strength, impact toughness and ductility, which are measures of a material's resistance to cracking (measured after fracture), can be significantly improved if the crack propagation direction and the grain flow are properly aligned. The optimum alignment occurs when the maximum principal stress (perpendicular to a potential crack or fracture) is aligned with the grain-flow lines. On testing the mechanical properties, it reveals that along the grain flow direction has 13.5% higher than the across the grain flow direction.

- by Shanmuga Prakash R
- •
- Microstructure, Mechanical properties, Welding, Grain size

Resumo: Para obter uma boa soldabilidade dos aços inoxidáveis ferríticos, na maioria das vezes, as empresas recorrem ao arames inoxidáveis austenítico em função de sua boa resistência mecânica, tenacidade e ductilidade. Arames de aço inoxidável ferrítico estabilizados ao nióbio e titânio estão sendo desenvolvidos para obter boa qualidade e baixo custo. O objetivo deste trabalho é estudar a influência da composição do gás de proteção (argônio puro e misturas com oxigênio ou dióxido de carbono) na composição química e microestrutura do cordão de solda do processo GMAW com transferência por curto-circuito. Foram utilizados dois arames eletrodos estabilizados (ER430Ti e ER430LNb) e um arame eletrodo não estabilizado (ER430) e como metal de base o aço inoxidável ferrítico UNS 43932. Os resultados mostraram que o aumento do dióxido de carbono no gás de proteção aumenta o teor de carbono no cordão de solda, tendo como conseqüência para o arame não estabilizado um aumento significativo da quantidade de martensita no cordão de solda, caso não observado de forma significativa com o aumento do oxigênio. Para o arame ER430LNb não verificou a presença da martensita de contorno de grão. O aumento tanto do dióxido de carbono como do oxigênio diminuiu os teores de Mn e Si para os arames ER430LNb e ER430, caso não verificado no arame ER430Ti.

- by Rodrigo Madeira
- •
- GMAW, SHORT CIRCUIT CALCULATION

Gas metal arc welding (GMAW) process is most widely used in industries for fabrication works, due to higher productivity. The weld quality depends on the process parameters of GMAW. This research investigates the influence of process parameters af ecting the mechanical properties of weldment. Thus, identification of the GMWA process parameters that significantly af ect the quality of GMWA processed parts is more important in terms of productivity. Then process environment has been assumed consisting of four variables like welding current, welding voltage, shielding gas, gas flow rate and wire feed rate. Taguchi optimization technique has been applied to determine the optimal limits, which can maximize the GMWA quality in certain environment. Signal to noise ratio (S/N ratio) were calculated for each data and used to obtain the optimum level of every input parameter. The study also shows that the use of the Taguchi Method has productively enhanced on the existing process parameters.

- by IAEME Publication
- •
- Optimization, Mechanical properties, Taguchi, GMAW

À minha esposa Doriani, pelo amor, carinho e incentivo, mesmo à distância. Aos meus filhos Leonardo e Laís, que me deram a motivação necessária. AGRADECIMENTOS Ao meu orientador Prof. Ivan G. Machado, pela orientação, contribuição técnica... more

- by Cristhian Will
- •
- GMAW

The aim of this paper is to presents a procedure of joining composite materials on aluminium base by using the GMAW process. The experiment included welding of the aluminium base composite with three different types of filler materials in the form of wire: AlMg4.5Zr, AlMg5 and AlSi5, and comparative analysis of the macroscopic and microscopic examination results. Base material was A356 Al-Si alloy composite containing 10 wt. % Al2O3. Average size of Al2O3 particles was 35 μm. The A356 matrix alloy was modified with the addition of 0.03 wt. % Sr. Composite was produced by the compocasting process. The results show that composite material with Al-Si matrix can be successfully welded by using the GMAW process. Results of macro and micro analysis show that the most favourable results were obtained by using the AlSi5 wire as filler material.

- by Aleksandar Vencl
- •
- GMAW, Aluminium Matrix Composite

"Welding is a reliable and efficient metal joining process. In many high temperature applications, it is necessary to join together components of same or different chemical, physical and mechanical properties. The joining of dissimilar metals is more challenging due to differences in the properties of the base metal welded. In this study, three-dimensional welding simulation was carried out in the FE software ANSYS in order to predict temperature, stress and strain in the joining of dissimilar materials.
"

- by Cristhian Will
- •
- GMAW
- by J. Edme
- •
- Occupational Health, Environmental Monitoring, ICP-MS, ICP-AES

Austenitic high-Mn based twinning-induced plasticity (TWIP) steels having their excellent tensile strength-ductility property combination, provide great potential in applications for structural components. In certain cases, these steels might also replace austenitic Cr-Ni stainless steels due to lower price and higher speed welding process. Hence a significant increase in the research activity on the weldability of TWIP steels have been proposed in the past decades. In this study, continuous butt welding of Gas Tungsten Arc [1st and 2nd pass] and Flux Cored Arc [2nd pass] welding of pipe elbows were examined. The weldments were characterized by metallography and microhardness tests. Tensile specimens, cut perpendicular to the welding line, were also tested and then subjected to fractographic examinations. Fusion zones, containing dendritic microstructure had lower hardness than HAZ and base metal. Internal cracks, present in the Flux Coated Arc welded samples, were responsible for lowering the tensile properties.

- by Maksudur Rahman
- •
- GMAW, TWIP steels, FCAW

- by Yuenyong Nilsiam
- •
- Engineering, Materials Science, Design, Digital Fabrication

Robotic welding is commonly viewed as one of the most effective ways to reduce costs and increase competitiveness in welding production. However, several requirements need to be taken into account when exploiting welding robotics. The main issues to be considered are the construction of the item to be welded, for example, the joint types, and accessibility to weld sub-assemblies such as stiffeners and cross supports. Furthermore, the type of base material places some restrictions upon the sensing technology applied. This work studied the robotic welding of an aluminum boat. Several sensor technologies were examined and welding experiments undertaken to clarify their potential. Redesign of sub-assemblies of the aluminum boat through modularization and selection of suitable welding processes for aluminum welding are found to provide the optimal solution for the adoption of sensor guided robotic welding.

- by Paul Kah
- •
- Mechanical Engineering, GMAW, Robotic Welding, Gtaw

Abstract: The effects of the hot stamping process and different hardfacing techniques, such as shielded metal arc welding (SMAW) and gas metal arc welding (GMAW), on the abrasive wear of ploughshares were investigated under field... more

- by Aysel YAZICI (Ph.D)
- •
- Wear, Soil and Tillage, GMAW, Hardfacing

Welding with fusible electrode and shielding gas (GMAW) using a shielding mixture based on CO2+ O2 is a procedure with high potential for joining low-carbon and low-alloy steels compared with traditional mixtures based on argon. One of... more

- by Juan Alberto Pozo
- •
- Materials Science, Experimental Design, Welding, Low carbon steel

Hybrid LASER-GMAW welding technique has been recently studied and developed in order to meet the needs of modern welding industries. The two sources involved in this process play, in fact, a complementary role: fast welding speed, deep bead penetration and high energy concentration can be achieved through the LASER beam, while gap bridgeability and cost-effectiveness are typical of the GMAW process.

- by Giampaolo Campana
- •
- Welding Engineering, Multidisciplinary, Welding, Stainless Steel

- by Daniel Jaime
- •
- Engineering, Radial Basis Function, Neural Networks, Welding

The research shows the characterization of mechanical properties in dissimilar steel welded unions: a structural steel ASTM A537 (I) overlap welded with an austenitic stainless steel ASTM A240 (304L) through semiautomatic electrical arc welding process protected by inert gas (GMAW); Argon is used as a protecting gas and austenitic stainless steel ASTM A240 (308L) as a supplier material. Samples were tested in not welded conditions so as to characterize the materials involved in the research, and they were also tested in welded conditions, not being submitted to pre and post welding Thermal Treatment (TT). Welded-based material samples were characterized through Optical Microscopy (OM) and Scanning Electron Microscopy (SEM), an inspection of Not Destructive Test (NDT) with penetrating liquids and ultrasound was also conducted. The following mechanical tests were completed, not only on the Base Metals (BM), on the Welding Join (WJ) as well: Vickers micro hardness profile, tension, and...

- by LEIRY CENTENO
- •
- Advanced Materials, GMAW

Gas Metal Arc Welding processes are generally used in almost every industrial segment. The process contain high levels of spatter generation, the wandering of the welding arc and the consequent waviness of the weld bead. The mechanical properties around heat affected zone (HAZ) and the weld bead geometry are greatly influenced by the welding parameters. In the present study, the influence of the heat input variation on the weld bead geometry and the heat affect zone has been analyzed. Taguchi based Orthogonal Array (L9) methodology was employed to optimize the process parameters i.e. welding current, gas flow rate and the welding speed. The weld quality has been assessed in terms of tensile properties of weldments such as microhardness, yield strength and ultimate tensile strength. The results revealed that combination of parameters had significant effect on microstructural feature of welded structure and hence weld strength.

- by IAEME Publication
- •
- Microstructure, GMAW, Tensile Strength

Cladding is usually employed for modifying surface of components and structures exposed to a corrosive environment. This process increases service life of a component or structure, thereby lowering frequent maintenance or replacement. Components or structures can be clad with corrosion resistant alloys up to a desired thickness. Arc welding processes are often used for cladding. Since clad materials are basically of different compositions, they are dissimilar in nature. Gas metal arc welding is often employed for cladding. In this work, cladding of austenitic stainless steel (316) is carried out on low alloy steel flat under different process parameters. Metallographic study and immersion type corrosion tests are performed on the clad specimens at different locations of it. The results of the metallographic study are discussed in this paper. Corrosion tests performed on clad specimens indicate substantially less corrosion pits present on the surface of the clad portions than that on the surface of the unclad portion. At a weld voltage of 26 V, weld current of 145 A, and weld speed of 535.8 mm/min, with a heat input of 0.338 kJ/mm, corrosion rate is observed to be the minimum in the domain of experiments conducted, and hence, may be recommended.

- by Santanu Das
- •
- Corrosion, Welding, Cladding, GMAW

Composite materials are increasingly used because of their physical, mechanical and tribological properties that are better compared to the properties of the matrix material. Within the group of composite materials with a metallic matrix, are composites based on light metals aluminium, magnesium and zinc. These composites have been used in many industries primarily because of its low density. Lightweight alloys usage in various industries reduce weight and hence energy consumption and greenhouse emissions. Composites based on aluminium are the most common, while the two mostly used reinforcements are silicon carbide (SiC) and alumina (Al2O3) [1-3]. The A356 Al-Si alloy is a casting alloy consisting of aluminium, silicon and magnesium. It is distinguished by good mechanical characteristics and high ductility, as well as excellent casting characteristics and high corrosion resistance [4]. The A356 alloy has low density (approximately 2.7 g/cm3) and belongs to the class of alloys whose...

- by Melisa Kočić
- •
- GMAW, Aluminium Matrix Composite

- by Yuenyong Nilsiam
- •
- Materials Science, Open Source Software, Welding Technology, Welding Engineering
- by Paul Kah
- •
- Mechanics, GMAW

Steel producers are continuously developing the mechanical properties and improving the weldability of high strength steels. Quenched and tempered steels belong to the one of the highest strength grades of structural steels with outstanding toughness characteristics due to the high temperature tempering. During fusion welding the thermal cycle irreversibly changes the microstructure and the mechanical properties of the base material, therefore an inhomogeneous heat-affected zone (HAZ) forms. In the HAZ hardened and softened zones occur. Due to the thermal cycles experiences during welding, these HAZs can exhibit significant losses in toughness when compared to the base metal. In real welded joints the HAZ properties can be analysed by conventional material tests to a limited degree; therefore physical simulators have been developed for the detailed examination of different HAZ areas. In the present research work the HAZ properties of a 960 MPa yield strength quenched and tempered steel (S960QL according to EN 10025-6) are investigated. Since the toughness reduction can be only partially handled by the adjustment of welding parameters, the possibility of local post-weld heat
treatment was examined. Based on preliminary physical simulations and welding experiments a medium heat input gas metal arc welding technology (t8/5 = 15 s) was selected for the HAZ simulations. The welding and the post-weld thermal cycles were determined according to the Rykalin 3D model. The effect of post weld heat treatment on the properties of the selected coarsegrained (CGHAZ), intercritical (ICHAZ) and intercritically reheated coarse-grained (ICCGHAZ) zones were investigated by electron microscopic, hardness tests and instrumented Charpy V-notch impact tests. The materials tests showed significant improvement of the toughness properties especially in ICHAZ due to the post-weld tempering, whilst the softening was acceptable.

- by Pedro Jose Ramos Perez
- •
- Radial Basis Function, Neural Networks, Welding, GMAW