Multi-Response Optimization in AA6063/SS304 Bimetalic Friction Welding using Taguchi Grey Relational Analysis

Influence of process parameters on hot tensile behavior of rotary friction welded In 718/AISI 410 dissimilar joints

In the present work, the dissimilar joints between C45 carbon steel and nickel-chromium 16NiCr6 steel rods were produced using rotary friction welding process. Statistical analysis based on response surface methodology (RSM), microstructural examination using scanning electron microscopy with backscattered electron diffraction (EBSD) and mechanical tests were performed to investigate the friction weld joints. The results showed that friction time and rotation speed were the most effective parameters on the weld joint quality with the highest t-ration of − 4.27, where the maximum bending strength of 1406.9 MPa was obtained at 2000 rpm for 13 s friction time. Increasing friction time to 13 s resulted in remarkable decrease in grain size (about 35%) at the weld interface, which increased the hardness (350HV0.1) and elastic modulus (260 GPa).Graphical abstract

Solid-state welding provides a distinct state of the art to joining various metal tubes. In contrast to other types of welding, dissimilar joining by solid-state welding maintains the integrity of its joints. Dissimilar joints of UNS S31803 and UNS S30400 tubes were carried out using rotary friction welding process. Three combinations of tube joints fabricated were, ASS to ASS, DSS to DSS and ASS to DSS joint. The tensile tests showed dissimilar weld joint achieved the minimum strength of ASS similar joint. Fractography for similar and dissimilar tube joints showed a ductile pattern of fracture with dimples and voids in the dissimilar tube weld. Microstructure analysis showed that diffusion bond line for similar and dissimilar joints confirms the sound weld tube joints. Corrosion test showed that among three combinations, ASS to DSS dissimilar joint had lesser corrosion rate than ASS to ASS or DSS to DSS similar joints.

In this experimental investigation, rotary friction welding (RFW) was employed to fabricate dissimilar Al-Cu joints, and the RFW variables were rotated against the ultimate tensile strength (UTS) in an effort to strengthen the dissimilar AA1100 and pure copper (Al-Cu) joint using response surface methodology (RSM) with a three-factorial design. Following this, micro-hardness, metallurgical characterization, and fatigue properties studies were done on the dissimilar joints fabricated under the optimized conditions. As a result of this investigation, the UTS of 208 MPa was attained as a maximum as the rotation speed was set at 1800 rpm, the friction time was 10 s, and the forging load was 5 kN. The dissimilar joint exhibits a better fatigue strength of 98.5 MPa when compared to the AA1100 base metal. At optimized conditions, the feature of the fracture image was found to be brittle due to the development of new compounds in the weld interface. A significant dip in micro hardness (52 Hv) was noticed in the region that connects TMAZ and HAZ of the AA1100 side of the dissimilar joint, which was concluded to be the weakest zone as the dissimilar joints were fractured in the same location during the tensile test. The observed results benefit the automotive sector, especially when fabricating components that require effective thermal management and weight reduction, like electrical connectors, heat dissipation systems, and radiators. For heat exchanger applications, improved fatigue strength in dissimilar Al-Cu joints is important because it guarantees longer structural integrity and improved durability.

Investigation of the joining technology of 3D-printed parts into a large physical model has become an important research topic. Rotary friction welding (RFW) is one of the friction welding methods. Understanding the weld interface temperature changes in the weld center zone during RFW is critical because it is related to the weld quality of the welded parts using RFW. Traditionally, the number of revolutions is constant in the RFW. However, rare investigations focus on the fatigue specimen fabricated by RFW with variable rotational speed. This study used RFW with varying rotational speeds to fabricate fatigue specimens. The ANSYS software was used to predict the temperature history of rotary frictionally welded dissimilar polymer rods fabricated by a computer numerical control (CNC) turning machine with variable rotational speed. The RFW experiment of ABS/PC dissimilar polymer rods was conducted to investigate the temperature history and compared with the simulation results. It was found that the temperature history profiles were in good agreement with the experimental and simulation results. Compared with the weld interface heating rate obtained from the experimental results, the simulation results has average discrepancy rate about 4.48 %. Compared with the maximum temperature of the weld interface obtained from the experimental results, the simulation results has average discrepancy rate about 3.16 %. The fatigue life can be increased by approximately 1.4 times. Finally, a database of rotary frictionally welded dissimilar polymer rods fabricated by a CNC turning machine with variable rotational speed was proposed. The average Shore A surface hardness at the weld interface was enhanced by approximately 18 % compared to the base ABS material.

A solid-state joining approach to manufacture of transition joints for high integrity applications

ABAQUS is a powerful software for simulating nonlinear material models with complex thermo-mechanical behavior. Its robust capabilities make it particularly suitable for simulating the Rotary Friction Welding (RFW) process. In this study, ABAQUS was utilized to simulate the RFW process of AA6061 aluminum alloy, focusing on key aspects such as weld morphology, temperature distribution, and axial shortening. The simulation results were analyzed and validated against theoretical foundations of the RFW process and previous research, demonstrating the model's high reliability. These findings highlight the potential for further development of the simulation model for various applications, aimed at enhancing the efficiency and effectiveness of RFW in industrial applications.

Effect of WC-Co cermet positioning and NiCr interlayer on the microstructure and mechanical response of the dissimilar WC-Co / AISI 304 L rotary friction joint

Joining phenomena and tensile strength of friction welded joint between Ti–6Al–4V titanium alloy and low carbon steel

Interfacial inhomogeneous plastic deformation during rotary friction welding of dissimilar AA2219-SS321 joint combination with AA6061 interlayer

Numerical simulation based upon friction coefficient model on thermo-mechanical coupling in rotary friction welding corresponding with corona-bond evolution

Transition of interfacial friction regime and its influence on thermal responses in rotary friction welding of SUS304 stainless steel: A fully coupled transient thermomechanical analysis

Evolution of interfacial contact during low pressure rotary friction welding: A finite element analysis

This work describes the effect of newly introduced faying surfaces on the microstructure and the mechanical properties of dissimilar weld joints of AA6063 and AISI304L alloys that are fabricated through the rotary friction welding process (RFW). The experiments were done as six different experimental methods (‘A’ to ‘F’) at 1300 rpm rotation, 18 MPa friction pressure (FP), 24 MPa upset pressure (UP) and 5 s friction time (FT) with the faying surfaces of hemispherical bowl and thread of 1 mm pitch on the weld specimens. The fabricated joints and the weld zones were characterized by macro and microstudy, energy dispersive X-ray spectroscopy (EDS) spectrums, tensile properties, Vickers microhardness, impact toughness and fractography. The results showed that these faying surface modifications strengthen the bonding between the weld specimens and influences the performance of the joints. The hemispherical bowl showed better results than the threaded surfaces. Axial shortenings were within the acceptable limit in the range of 20–27 mm. Macro and microstructural studies showed the defect-free weld joints and the strong bonding between AA6063 and AISI304L alloys. The hemispherical faying surface on AISI304L alloy formed a U-shaped weld interface (WI) in the dissimilar joints. EDS proved the formation of the Fe–Al intermetallic and the element ‘O’ at weld zone. The joint efficiency for all the methods was around ≥100%. Maximum tensile strength was recorded as 238 MPa for method F. The threaded surface showed good hardness property nearby WI, and method A yielded maximum impact toughness for the joint.

In this paper, the effect of rotary friction welding on hardness and microstructures of weld zones and base metal zones of Ti-6Al-4V and Cu have been investigated. A rotary friction welding technique was used to perform dissimilar joining of Cu and Ti-6Al-4V bars. Friction welding process parameters were optimized process parameters of a 5-ton rotary friction welding machine. The upset pressures were applied from 30 kg/mm2, 40 kg/mm2 and 50 kg/mm2. The dissimilar joint was successfully formed at upset pressure of 50 kg/mm2. The friction welded joints were failed in drop test after welding at the lower upset pressures (30 kg/mm2 and 40 kg/mm2).The hardness and microstructures were characterized for weld joint formed at 50 kg/mm2. The weld zone, base metal and weld interface and base metals were analysed to understand microstructures and elemental diffusion of Ti and Cu. The welded specimens were examined by using an optical microscope and scanning electron microscope. Grain refinement was seen in Cu near the interface of the joint whereas in the case of titanium circular patterns of grains were seen near the interface of the joint. The micro hardness of Ti-6Al-4V was increased from 307 HV to 365 HV and for Cu increased from 240 HV to 290 HV. Intermetallic compounds such TiCu4 and Ti2Cu were found at weld zone by X-ray diffraction analysis.