Weld Material Research Articles

Study on explosive welding A1060/3D-Printed-SUS316L

Explosive welding has been extensively harnessed to create composite materials for various applications in recent years. Integrating 3D-printed metal materials in explosive welding is important for future research and the broader application of 3D-printed materials in practical scenarios. In this study, 3D Printing-SUS316L/A1060 was employed for explosive welding to assess the feasibility of using 3D printed materials in this process and to examine the microstructural changes at the interface, emphasizing changes in the pores of the 3D-printed materials during welding. The resulting joint microstructures were analyzed using a scanning electron microscope (SEM) alongside an energy-dispersive X-ray spectroscopy (EDS) system and electron backscatter diffraction (EBSD). Tensile, three-point bending, Vickers-hardness, and nanoindentation tests were conducted to investigate the mechanical properties. X-ray computed tomography (XCT) scanning was utilized to observe the weld material in three dimensions and measure porosity. Moreover, ANSYS AUTODYN numerical simulation was employed to study the welding interface evolution mechanism and pore changes and further investigate the explosive welding window. The results indicate that explosive welding can successfully merge 3D-printed SUS316L and pure aluminum A1060. Both microstructure investigation and mechanical property testing validated that the bonding was of good quality, and simulation and welding windows corresponded with the experimental results.

Analisis Potensi Bahaya Dengan Metode Hazard Identification and Risk Assesment dan Failure Mode Effect Analysis Pada PT.XYZ

PT. XYZ is a manufacturing company that specializes in making food and soft drinks. According to the company, there have been no reports of incidents during the production process. However, based on empirical findings obtained from observations in the maintenance section, especially in the field of assembly work, many near misses or near misses occur during the implementation stage. Efforts that need to be made to overcome this are by identifying activities that are at risk of causing work accidents. In this research, work accidents were identified using the HIRA method, which then based on the results of the HIRA, improvements were then carried out based on priorities using the FMEA methodology. In the grinding machine assembly process, it is known that there are six work activities including material selection, grinding, welding, painting, assembly, and machine trial. The HIRA identification results show that there are 8 activities that have a medium risk of work accidents, for which FMEA analysis will be carried out. The results of the FMEA analysis show that the motor selection activity for the grinding drive has the highest RPN value so the control in the work is carried out using the help of a chain block, ensuring the chain block is in prime condition, using complete personal protective equipment, carrying out work according to SOP, and using chain block according to capacity.

Post-weld heat treatment effects on microstructure, crystal structure, and mechanical properties of donor stir–assisted friction stir welding material of AA6061-T6 alloy

Post-weld heat treatment effects on microstructure, crystal structure, and mechanical properties of donor stir–assisted friction stir welding material of AA6061-T6 alloy

이종금속 용접에 사용되는 ER309L 용접금속의 기계적 성질에 미치는 후열처리의 영향

STS309(L) is widely used as a welding material for dissimilar welding of carbon steel and stainless steel. In general, austenitic stainless steel does not perform post-weld heat treatment (PWHT) to relieve thermal stress even after welding due to a sensitization. However, in the case of dissimilar joints between carbon steel and stainless steel, PWHT is often performed to relieve the thermal stress resulting from welding in carbon steel. Nevertheless, the stainless steel side may be subjected to heat treatment during PWH, leading to a deterioration in the mechanical properties of the stainless steel. Therefore, in this study, we investigated the effects of PWHT duration on the ferrite volume fraction, ferrite number, and mechanical properties. Through this, we aimed to determine the maximum post-heat treatment duration. The chemical composition did not change with an increase in the post-heat treatment time; however, the elongation and ferrite number decreased, and the tensile strength increased.

Twenty Years of Progress in Microstructure Modelling for Ultrasonic Testing, from Shielded Metal Arc Welding to Gas Tungsten Arc Welding: An Analysis for Future Developments

To ensure and to demonstrate the mechanical integrity of a welded structure, precise ultrasonic testing (UT) is often mandatory. The importance of the link between nondestructive testing (NDT) and the assessment of structural integrity is recalled. However, it is difficult to achieve great efficiency as the welding of thick and heavy structural part produces heterogeneous material. Heterogeneity results from the welding process itself as well as from the material solidification laws. For thick components, several welding passes are deposited, and temperature gradients create material grain elongation and/or size variations. In many cases, the welded material is also anisotropic, this anisotropy being due to the metal used, for example, austenitic stainless steel. At the early stages of ultrasonic testing, this kind of welded material was considered too unpredictable, and thus too difficult to be tested by ultrasounds without possible diagnosis errors and misunderstandings. At the end of the 1990s, an algorithmic solution to predict the material organisation began to be developed using data included in the welding notebook. This algorithm or modelling solution was called MINA. This present work recalls, in a synthetic form, the path followed to create this algorithm combining the use of solidification laws and the knowledge of the order of passes in the case of shielded metal arc welding (SMAW). This work describes and questions the simplifications used to produce a robust algorithm able to give a digital description of the material for wave simulation code. Step by step, advances and demonstrations are described as well as the limitations, and ways to progress are sketched. Recent developments are then explained and discussed for modelling in the case of gas tungsten arc welding (GTAW), in addition to discussions about 3D modelling for the future. The discussion includes alternative ways to represent the welded material and challenges to continue to produce more and more convincing weld material model to qualify and to make use of UT methods.

Experimental evaluation of aluminothermic welds

The article presents a study of the mechanical processes occurring during the aluminothermic reaction using experimental methods (strain gauges, digital image correlation, thermography, scanning electron microscopy, profilometry). The aluminothermic reaction is a highly efficient welding method due to its exothermic behaviour, however, it places considerable demands not only on the welding technique, but also on the capabilities of the experimental methods used; these limitations are also discussed in the article. The aluminothermic reaction is associated with the formation of a localised heat source with a time evolution dictated by the technological procedure, which manifests itself in heat propagation to the surrounding weld material. The unequal evolution of the temperature field is the fundamental cause of the appearance of the heat affected zone or local deformations or surface curvature, which was the focus of the experimental methods deployed above and the results of which are shown in the article.

Investigation of structural-phase transformations of weld metal and in the heat-affected zone during laser welding

The use of laser equipment is one of the promising ways to create innovative and highly efficient technologies in the production of ship structures. The main advantages of using laser technologies in the production of marine equipment are increased productivity by increasing the speed and reducing the number of welding passes, improving the quality of welded joints due to the accuracy of the assembly of structures and the level of automation, reducing the level of residual stresses, warping and leash due to significant localization of the heating and penetration zone compared with arc welding technologies, a significant reduction in the consumption of welding materials or their complete exclusion due to the smaller dimensions of the geometry of the cutting edges and the width of the assembly gaps. The mechanical properties of the welded joint are determined by the composition of the steel and its structure. The structural- phase transformations of the weld metal are determined by the temperature-time parameters that occur in the seam zone itself and in the heat-affected zone. Laser welded joints are formed under conditions in which thermal cycles differ significantly in depth and width of the weld, so the mechanical properties of the joint are determined by local changes in the structure of the seam metal and heat-affected zone. The issues of formation of the phase composition of the seam zone and heat-affected zone during laser welding are examined in the paper. On the basis of numerical modeling of thermal processes and structural- phase transformations of weld metal and heat-affected zone accompanying laser welding, a method for quantifying the volume fraction of structural- phase components of weld metal and heat-affected zone is proposed. The proposed calculation algorithm avoids solving the equation for the amount of the volume fraction of the structural- phase components of the metal at each step of the calculations.

Behaviour of high strength steel butt joints exposed to arctic low temperatures

The present study investigated the tensile behaviour of high strength steel (HSS) butt joints exposed to arctic low temperatures. Two HSS grades, namely Q890 and Q960, with thicknesses of 6 mm and 8 mm, were employed. Single-V-groove butt joint specimens were fabricated by means of robotic gas metal arc welding using 1.2 mm-diameter ER100S-G and ER120S-G feedstock wires. The single-V-groove and butt joint tensile specimens were designed according to the Structural Welding Code-Steel AWS D1.1. Metallographic observations and Vickers hardness tests were performed on five series of HSS butt joint. Moreover, a total of 25 butt joint specimens were tested under uniaxial tension in a liquid nitrogen cooling chamber, with temperatures ranging from -75 °C to 25 °C. The stress-strain histories, tensile strengths and failure modes of the HSS butt joints exposed to arctic low temperatures are fully reported. The influence of low temperature exposure, parent steel grade and weld material selection on the tensile behaviour of the HSS butt joints is discussed. Based on the test results, recommendations for weld material matching for Q890 and Q960 HSS butt joints are provided. Additionally, prediction equations for HSS butt joint strengths exposed to arctic low temperatures are proposed using the best subset regression analysis. The findings from this study contribute to a better understanding of the behaviour of HSS butt joints under arctic low temperatures, and can be used to inform design and fabrication practices of HSS structures in cold environments.

Friction stir welding of carbon black reinforced high-density polyethylene tube-to-tubesheet joints

Industrial heat exchanger applications dealing with highly corrosive fluids demand the use of thermoplastic heat exchangers because of the chemically inert and anti-fouling nature of the thermoplastics. A non-conventional joining framework, based on the friction stir welding (FSW) technique, is used to form high-quality thermoplastic tube-to-tubesheet joints (TTJs). The proposed technique has potential applications for thermoplastic shell-and-tube heat exchangers and piping industries (as flange-to-pipe joints). In this work, the tube and tubesheet materials made of carbon black reinforced high-density polyethylene were used. The effect of different FSW parameters (rotational speed, plunge depth, tube protrusion, dwell time) on the tube pull-out behavior was investigated. The FSW technique showed capabilities at a wide range of operating conditions. The highest load bearing capacity of 517 N was achieved using the FSW process, much higher than adhesive joints. Also, it provides higher extensions at maximum load than adhesive joints, with the highest extension of 5.161 mm. Two FSW cases provided high leak paths of 77% and 58% remaining sheet thickness (greater than tube thickness) along with high load bearing capacity and corresponding extensions. The macroscopic and SEM-based fractographic studies illustrated three types of failure behavior: ductile, brittle, or mixed depending on the FSW process conditions. The DSC results showed no significant crystallinity changes in the weld material. The TGA results showed no significant thermal degradation occurring in the weld material. Further, the FTIR analysis indicated possible oxidation of the weld material. The capability to form TTJs with high leak path, high load bearing capacity, and no significant material degradations makes the FSW technique suitable for thermoplastic shell-and-tube heat exchanger applications.

Thermocapillary convection in a laser-heated Ni melt pool: A molecular dynamics study

Thermocapillary convection was investigated in a metallic system of pure Ni, at the nanoscale, by molecular dynamics. The system interface was irradiated by a heat flux, mimicking a focused laser source. The melt pool was submitted to a large temperature gradient that modified the surface tension along the interface. In liquid metal, because surface tension typically decreases with increasing temperature, the result is a gradient of surface tension along the free surface. The liquid metal, therefore, started to flow in the direction of high surface tension. Two counter-rotating convection cells developed, characteristic of those observed in welding and other material processing. A systematic estimation of relevant parameters in hydrodynamics allowed us to interpret the results in terms of Prandtl, Marangoni, and Péclet numbers. This study demonstrates the influence of laser power and system size on pool shape and flow characteristics.

Miniature specimen tests and fracture model of heat affected zone material

AbstractThe paper investigates the mechanical properties of the heat affected zone (HAZ) material near welds and compares the properties to those of the base metal and weld materials. A dedicated experimental set‐up was designed and manufactured to test miniature specimens with a cross‐section width in the range of 1 mm to 2.5 mm and a parallel gauge length of less than 10 mm. To identify the HAZ of the welded connections, a macro‐etching technique was adopted, and the shape and size of the HAZ were measured. Afterwards, miniature specimens were extracted from the base metal, weld and HAZ in both the longitudinal and transverse directions of the weld, and subsequently tested in the specialised experimental set‐up. The miniature specimens not only included the normal rectangular plate‐type specimen, but also the notched round bar and grooved plane strain types of specimens. Hence, the stress‐strain curve and fracture strains under various stress states were obtained from the tests. The validity of the Lode angle Modified Void Growth Model (LMVGM) was investigated using the experimental data, and the fracture loci of the base metal, weld and HAZ in both the longitudinal and transverse directions were identified.

3D‐printing with steel on thin sheets for application in free form façade construction: welding process development and material properties

AbstractWire and Arc Additive Manufacturing (WAAM) became a significant research field in structural engineering over the past years. It offers the opportunity to apply material fast and precisely, following the load path, inducing effective material consumption. Considering free‐formed sheet‐metal façades, to date large thicknesses are necessary to maintain the final shape and load‐bearing capacity that however causes high material consumption and costs during the construction processes. Hence, WAAM could be an opportunity to reduce the amount of mild steel used for free‐form façades. As part of a research project at TU Darmstadt, 1 mm thick free‐form sheet‐metal façades elements have been manufactured using WAAM. Due to precisely welded lattice structures, placed on the backside of the metal sheet, the reinforcement will be ensured. Wide studies on welding parameters focused on a stable process without damaging the later frontside of the façade panel and on process optimization. In addition, material properties of the welding material have been determined to check its usability in façade construction.

Evolution mechanism of interfacial microstructure and its effect on failure in dissimilar metal welds containing ferritic heat resistant steels

This study investigated the behaviour and mechanism of interfacial microstructure evolution during long term high temperature exposure and the effect of interface structure on creep failure in the dissimilar metal welds (DMWs) involving ferritic heat resistant steels with nickel-based filler metal. The welding of nickel-based and ferritic materials led to the formation of interfacial martensite layer in the ferritic steel side of DMW. During long term high temperature exposure, interfacial martensite transformed to ferrite due to C diffusion and migration in the micro-region near the BCC/FCC interface between the martensite layer and the weld metal. The martensite-ferrite transformation was attributed to the large C chemical potential gradient caused by chemical composition gradient. Under creep condition, the failure of DMW was prone to occur along the weld metal/ferritic steel interface, which was related to strain concentration around the interfacial ferrite formed during service. Hence, the relationships between interface structures before and after service and interfacial failure in the DMWs were clarified.

Certification of welder for tungsten inert gas welding in unmanned aerial vehicle systems

Aluminum and its alloys is one of the extensively used non-ferrous metal in aerospace engineering applications due to its excellent properties like higher strength to weight ratio, non-magnetic property, high thermal conductivity, good machinability, recyclability, and excellent formability. However, welding of aluminum and its alloys has always been a challenge due to drastic reduction in strength near heat affected zone (HAZ). Due to softness, ductility, lower melting point of aluminum and its alloys impose additional challenges to weld aluminum alloy components. Due to this, the quality and quantum of skill set needed to weld aluminum alloy joints for flight critical components is much more than that of welding of ferrous materials. The qualification and certification of welder is one of the prime requirements in welding applications especially in aerospace industry. This paper mainly discusses the various aspects involved in qualifying and certifying a welder for tungsten inert gas (TIG) welding process of aluminum alloys, which is treated as one of the special processes. The welder certification is a written verification that weld joints produced by welder meets the prescribed standard of welder performance. It is to verify the ability of an individual to execute a qualified welding procedure specification to produce a sound weld. Aluminum alloy 6xxx series is considered for base metal for sample preparation and weld joint assessment studies, as it is one of the prevalently used aluminum alloy material in unmanned aerial vehicle (UAV) applications. Weld samples are prepared as per internationally practiced standards and welding procedure specification (WPS) is recorded. Various mechanical tests carried out on weld samples during certification process are discussed in the paper. Weld joints are subjected to tensile testing, bending test and macro test. The certifying agencies are involved at every stage to ensure consistency of welder performance.

Preface

The 2023 9th International Conference on Applied Materials and Manufacturing Technology (ICAMMT 2023) was held in Qingyuan, China on April 24th–26th, 2023 (hybrid conference). The series of ICAMMT workshops was created in 2014 with the aim to be an interdisciplinary incubator for the worldwide exchange of innovative ideas and information about the latest research results.At ICAMMT 2023, we wished to bring together a broad community of researchers from different branches of the rapidly developing science to discuss the fundamental theoretical challenges as well as experimental and applied aspects of many practical problems. The program of ICAMMT 2023 was prepared based on three categories.ICAMMT 2023 attracted about 200 participants from about 15 countries. There were four invited speeches and many regular oral talks in the morning and afternoon sessions. The speakers are: Prof. Xun E (Bohai University, China), working on Internet of Things Intelligent Computing, Food Safety Informatization; Prof. Honggang Dong (Dalian University of Technology, China), committed to dissimilar materials joining technology and metallurgy, composition design of welding materials, and numerical simulation of welding processes; Prof. Robert G. Landers (University of Notre Dame, America), devoted to modeling, analysis, monitoring, and control of manufacturing processes, and the estimation and control of lithium-ion batteries and hydrogen fuel cells; Prof. Yusri Yusof (Universiti Tun Hussein Onn Malaysia, Malaysia), interested in the manufacturing of smart devices & technology development and digitalization & Retro-Fit CNC machines. The keynote speeches allowed all the participants to interact with the speakers and people around as well as get some novel insights.The papers submitted to this volume were carefully reviewed by referees, covering topics on: Corrosion of Materials and Surface Treatment Technology, Mechanical Behavior & Fracture, Mechanical Transmission Theory, Vibration, Noise Analysis and Control, Measure Control Technologies and Intelligent Systems, Micro-Electronic Packaging Technology and Equipment, etc.. We are very grateful to the referees for their very efficient and thoughtful review actions. A few submitted papers were unfortunately not included based on the referee reports.We are very grateful to the members of the Technical Committee for their time and hard preparing the program of ICAMMT 2023. We also appreciate the behind-the-scenes work of the members of the Organizing Committee in preparing the conference site, arrangements for excursions and accommodation, handling the financial support for participants, and so on. Finally, we acknowledge the publishing support from Journal of Physics: Conference Series.The Committee of ICAMMT 2023List of Committee Member is available in this Pdf.

Utilization of probability-based multi-objective optimization in material welding and machining

Utilization of probability-based multi-objective optimization in material welding and machining

Fatigue Behavior of Rotary Friction Welding of Acrylonitrile Butadiene Styrene and Polycarbonate Dissimilar Materials.

Understanding the fatigue behaviors of weld joints is significant in engineering practice. Rotary friction welding (RFW) can join the additively manufactured polymer components. Until now, no research has focused on the fatigue behavior of polymer components jointed via RFW. This study investigates the fatigue life of ABS/PC dissimilar components fabricated via RFW and proposes the fatigue mechanism based on the failure structure. This work uses five different cyclic loads and rotational speeds to investigate the fatigue life. The fatigue life of the RFW of ABS/PC dissimilar rods is better compared with the pure ABS and pure PC specimens due to weld and integrity microstructural changes resulting from the combination of ABS and PC materials. The number of cycles until the rupture of RFW of ABS/PC dissimilar components (y) can be determined by the cyclic load (x) according to the prediction equation of y = -838.25x2 - 2035.8x + 67,262. The fatigue life of the RFW of ABS/PC dissimilar components increase with the increased rotational speed. The number of cycles until rupture (y) can be determined by the different rotational speeds (x) according to the prediction equation of y = 315.21x2 + 2710.4x + 32,124.

RANCANG BANGUN PROTOTIPE PREPARASI MATERIAL RESISTANCE SPOT WELDING

The manufacturing process in the automotive industry is in dire need of resistance spot welding machines. Because it was easier to use, highly effective, and effective in functioning. However, there were sometimes still connection problems that were still of poor quality, both nuggets and areas that are subject to electrode pressure. To get a quality welding connection, a machine was needed that was able to carry out good material preparation in the form of sanding, able to set the welding current analogously, able to set the time with an automatic timer, able to apply pressure on the electrode measurably during the welding process. The research aimed to design a prototype of resistance spot welding material preparation that could adequately carry out material preparation and welding using a Bluetooth system connected to a mobile phone. The research methods carried out were as follows: first, designing the machine using Autodesk Inventor software, then the device was made with a focus on material preparation prototypes, then the machine elements were made for the material clamping rail, then the machine elements in the control section using Bluetooth connected to the mobile phone, the machine was tested, then the connection quality testing process was carried out on the tensile testing machine. The results showed that the design results had been made using elbows and iron plates with threaded rails with a length of 650 mm, which became material clamping rail grooves with a drive using window motors controlled by Bluetooth on the Arduino circuit. The test results of welded joints show that the roughness is 0.20 μm which has the highest tensile strength.

Influence of Additives on the Mechanical Characteristics of Hardox 450 Steel Welds.

The aim is to overcome the issues of high-hardness material welding by different additives used to achieve the desired improvements. The research is focused on Hardox 450 steel welding and factors to be considered in order to maintain the required mechanical properties of the weld. The selection of best suited welding materials or additives, including filler metals and shielding gases, are within the important factors to be taken into account. During the welding of Hardox 450 steel, cobalt, nickel, tungsten and titanium additives and cobalt and tungsten mixture additives were used and their influence on the microstructure and mechanical properties of the fusion and heat-affected zones was investigated. The microstructure of the weld zone is related to certain mechanical properties of the weld and heat-affected zone, such as hardness, tensile and bending strength, yield strength, strain at ultimate tensile strength, the Young's modulus and elongation. Research has shown significant differences in the mentioned parameters depending on specific additives used in the welds. It can be concluded that tungsten, used as an additive, increased the hardness of the heat-affected and fusion zones up to 478 HV; the combined presence of cobalt and tungsten additives improves the strength of the seam up to 744 MPa during tensile; and in the case of bending, nickel, when used as an additive, increased ductility (the bending modulus reached the limit of 94 GPa) and at the same time, decreased the risk of cracking. The obtained results highlight the possibilities for strengthening the welded joint of Hardox 450 steel using different additives or their mixtures. The research conclusions and recommendations aim at improving the quality and mechanical properties of welded Hardox 450 steel joints in various applications.

Analysis of laser welding on dissimilar materials with the influence of adding interlayer

The laser welding of dissimilar materials poses several challenges in practical applications, such as molten pool instability, the formation of intermetallic compounds (IMCs), and cracking caused by differential thermal stresses. In this study, we investigated the impact of incorporating a nickel (Ni) foil as an intermediate layer on lap joints of dissimilar materials (SS304 and Al6061) welded using the continuous laser welding (CLW) technique. The thermomechanical simulation accurately predicted the width and depth of SS304–Ni–Al6061 joints, with deviations of merely 3.92% and 19.04% from experimental results, respectively. Residual stress analysis revealed that the addition of a nickel foil reduced residual stress in the heat-affected zone (HAZ) and improved joint fatigue life. Furthermore, the incorporation of 0.1 and 0.2 mm Ni foils enhanced joint strength and effectively suppressed the formation of brittle intermetallic compounds, resulting in a remarkable maximum lap shear force of up to 1026 N. The simulation results for the shear load-displacement curve displayed excellent agreement with experimental data, with a deviation of only 6%. Notably, joints with the Ni foil demonstrated a greater ability to prevent crack formation caused by thermal expansion mismatch compared to joints without the Ni foil. The Ni interlayer served as a diffusion barrier and stress buffer, promoting a more uniform microstructure and reducing the likelihood of crack formation in bonded materials. Overall, this study comprehensively investigates the impact of incorporating a nickel interlayer on laser-welded lap joints of dissimilar materials. The findings offer valuable insights for practical applications, enabling improved joint strength, reliability, and crack resistance in laser welding dissimilar materials.