Papers by Keyword: Friction Welding

Abstract: In this study, the Al₂O₃ round bar and Al-Si12CuNi (AC8A) round bar were joined by friction welding. AC8A is a typical piston material treated by the heat treatment T6. The parameters of the joining condition are friction time and upset pressure. SEM observed the microstructure at the interface region of joined materials. 1) Judging from these photographs, the damages to the microstructures at the interface region of joined materials by upset pressure are more significant than those caused by friction time. 2) The relationship between the joint conditions and mechanical characteristics from three points of bending test results for the joint material specimens. 3) The residual stresses around the interface were measured by the Raman spectroscopy method. There is a possibility that the friction welding conditions are correlated to the residual stresses.

Abstract: The Swiss-type automatic lathe is designed for continuous mass production of the same product. In the research, the authors propose a combined turning process in which a joining process using the frictional welding method is introduced into the automatic lathe. If the joining process is performed with a Swiss-type automatic lathe, it is expected that the problem of a large amount of residual material due to the mechanical structure can be solved. Generally, the friction welding method is performed by a dedicated machine and is pressure controlled by a hydraulic power source, however in the case of an automatic lathe, friction welding is controlled by the feed length and feed rate. The low rigidity of automatic lathes is also concerned. In the study, the authors investigated the tensile strength and rotational bending fatigue strength of the A6061 bonding material to investigate and quantitatively evaluate the optimum friction welding conditions that can obtain good bonding results in the friction welding method using a multi-axis automatic lathe. Upset speed was the most influential factor for tensile strength and friction rotation speed was good at about 4000 rpm. This fact suggests that excessive heat input leads to a decrease in tensile strength. The tensile strength was equivalent to that of the annealed material. It also seems that the air-cooled annealing phenomenon occurs during the friction welding process. The results of rotational bending fatigue strength were similar to those of the annealed material. It is clarified that friction welding with an automatic lathe is feasible, however, the strength of the bonded material is reduced to the same level as that of the annealed material.

Abstract: The economical and highly productive method of welding is used to join a dissimilar material. The quality of welded joint with high efficiency is obtained from friction welding process. The intention of the current work is to assess the progress of solid state juncture of dissimilar materials of aluminum 6082 and copper. The strong joints were developed using frictional heat and external pressure. The friction welded joints were tested under welding strength and surface analysis using scanning force microscopy (SFM). Rotational speed, friction pressure and forging pressure were used to evaluate the performance of the welded joints. Optimize the welding strength and hardness was attained through taguchi method.

Abstract: The forged superalloy Inconel 718 and cast superalloy Mar-M247 were joined via friction welding. The welded zone was recrystallized and formed a thin representative layer on the forged superalloy side adjacent to the interface. The effect of the creep property of the welded layer on the behavior of the joint under creep loading was investigated via numerical simulations. Despite the welded layer being relatively narrow (approximately 200 mm), it significantly effects the stress state and the creep damage parameters in and around the welded zone. When the creep rate of the welded layer is lower than that of the base alloy, the stress concentration is dramatically increases adjacent to the interface. However, the creep rate of the welded layer creep rate is higher than that of the base alloy, the interface stress concentration is reduced. The creep strain and stress exhibited an out-phase relation.

Abstract: Friction welding (FRW) is an important commercial solid-state welding process in which coalescence is achieved by frictional heat combined with pressure. The objective of this work is to analyze the microstructure and the mechanical behavior of the copper alloy UNS C64200 – bronze-aluminum-silicon, as well as to raise the ideal welding parameters so that there is adequate weldability after process of continuous-drive friction welding. Regarding the analysis of the microstructure, scanning electron microscopy was used to characterize phases. The mechanical properties were evaluated by means of a hardness test of the center of the welded joint, traversing the entire extent of the thermally affected zone. Results show that the UNS C64200 alloy, when subjected to conventional friction welding, behaves satisfactorily in terms of weldability, without the appearance of cracks or defects arising from the temperature characteristic of this process, as well as good hardness with values above the minimum established in norm and higher than the base material.

Abstract: Currently, the most promising high-tech and productive process is friction stir welding. An important element of this technology is the determination of the material temperature in the stir zone, which can be determined by calculation based on the amount of heat input introduced into the welding zone. To determine this value, experimental of the dependence of heat input on the tool rotation speed and welding speed were carried out. For this, a scheme of experiments has been selected in which the material to be welded (aluminum alloy AMg5) is modeled as an experimental tube with a diameter of 20 mm, and the tool (made of tool steel R6M5) is modeled as a working plate. On the designed and manufactured stand, studies of the dependence of the heat-liberation value for the speeds of rotation of the experimental tube 42-105 rad/s were carried out. In this case, due to the pressing force of the experimental tube and the working plate, a constant temperature of the place of friction was maintained. The obtained experimental data were used to calculate the heat-liberation value and heat power on each concentric ring 2 mm wide at the end of the working tool with a diameter of 20 mm, as well as the total heat power for different speeds of rotation and welding.When carrying out experiments on the bench, heat losses were determined by thermal conductivity along the rod on which the experimental tube is fixed, as well as from the working plate made of tool steel through the gasket onto the working table and by convection from the surface of the rotating experimental tube into the environment. The calculation results showed that each of these losses does not exceed 3-10%. These losses are taken into account in the heat supply calculations.

Abstract: In the present study, dissimilar friction welding between super alloy 718 and carbon steel friction welded to evaluate the formation of microstructure in the weld interface and in superalloy 718. The temperature during friction welding at weld interface was recorded to determine the temperature effect on the microstructural changes on alloy 718 side. The finite element modeling of weld interface temperature, deformation and stresses were evaluated and validated with the experimental results. The microstructural observation along with the weld interface and adjacent regions are studied. The effect of friction welding on superalloy weld interface and microstructural formation were investigated under electron backscattered diffraction analysis to evaluate the grain size measurements. The effect of thermomechanical action on the microstructure was evaluated by texture analysis.

Abstract: This work, Seamless Austenitic 213 tube is welded with Seamless Austenitic 387 tube plate through friction welding of tube to tube plate using an external tool (FWTPET) method in presence of backing block by using clearance fit method. Further, the analysis of microstructural features on the interface of weld exhibit that the FWTPET is able to generate flawless welds. In all nine various work specimen which welded under the various circumstances, the hardness value, tensile strength have taken. In this work, two type of specimen has taken where one kind is the tube which contains no hole and another one is with the hole in the circumference. 806.28 MPa and 746.5 MPa were the optimum strength for the workpiece which is not a having a hole and having the hole on the circumference.

Abstract: In this study, Friction Welding of Tube to tube-Plate using an External Tool (FWTPET) is carried out by joining SA213 tube and SA387 tube plate alloying materials using an external tungsten tool by close fit methods in absence of backing plate without hole on the circumference of the tube for superior mechanical and metallurgical properties. The optimization techniques such as Taguchi L₉ and Analysis of Variance (ANOVA) is used to endorse the capital joint strength. The output parameter (TS) and input factors (tool rotational speed, tube projections, depth of cut) are designated for the study. The heat that produces from tool pin, dissipates to the tube and the tube plate during FWTPET process. The grain size measurement, x-ray diffraction (XRD) phase analysis, radiography test is carried out after FWTPET process. In this research work, FWTPET process is carried without hole on the circumference of the tube, further FWTPET process is also compared by without employing supporting arrangement. Excellent joint strength of 762.2 MPa is achieved with the absence of supporting specimen which without hole on the circumference of tube for the tool rotational speed of 1300rpm. Keywords: Friction welding, FWTPET, Analysis of Variance (ANOVA), Optimization techniques, Tensile strength

Abstract: We evaluate the properties of friction welded steel tubes in terms of the relationship between microstructures and mechanical properties. For this work, steel tubes with a diameter of 60.5 mm, which has a thickness of 3.3 and 2.2 mm, was prepared by length of 170 and 70 mm, and friction welding was conducted at a rotation speed of 2,000 rpm and upset time of 5 s, respectively. Applying the friction welding led to the notable grain refinement so that average grain size was refined from 15.1 μm in base material to 4.5 μm in welded zone. These refined grains achieved the significantly enhanced microhardness (20% higher) and a slightly higher tensile strength relative to the base material, respectively. In particular, the tensile tested specimens showed the fracture aspect at the base material zone not at welded zone, which means the soundly welded state.