Direct Drive Friction Welding Research Articles

Direct Drive Friction Welding Influence on Metallurgical, Mechanical, and Electrochemical Properties of AISI 316

Direct Drive Friction Welding Influence on Metallurgical, Mechanical, and Electrochemical Properties of AISI 316

Tensile joint strength characterizations for Cr-Ni-Mo steel (AISI 316) during direct drive friction welding process

Tensile joint strength characterizations for Cr-Ni-Mo steel (AISI 316) during direct drive friction welding process

Effect of Forge Application on Microstructural and Mechanical Properties of AISI 316 Using Direct Drive Friction Welding Process

Effect of Forge Application on Microstructural and Mechanical Properties of AISI 316 Using Direct Drive Friction Welding Process

Direct drive friction welding of a multi-phase Al13Cr23.5Fe20Co20Ni23.5 high-entropy alloy

Al13Cr23.5Fe20Co20Ni23.5 high-entropy alloy with three phases (face-centered cubic [FCC], A2 and B2) was joined successfully by direct drive friction welding. The microhardness of the welded samples gradually increases as approaching the weld interface, which was related to the microstructural evolution across the weld interface. The weld joint can be divided into four regions: dynamic recrystallisation zone, thermal-mechanically affected zone, heat affected zone and base metal. It is found that the volume fraction ratio of FCC to body-centered cubic (BCC) (A2+B2) phases slightly decreases as approaching the weld interface. The hardening of the joint is attributed to the refined structure, large deformation and the increased volume fraction of the hard BCC phases in the weld joint.

Direct Drive Friction Welding Joint Strength of AISI 304

The present study describes the effect of friction welding process on mechanical and metallurgical properties of AISI 304 steel. The joints were made by direct drive friction welding (DDFW) machine, while the characteristics of friction welded joints were evaluated by macro-microstructure, microhardness, tensile test with 4 mm and 6 mm effective diameter, and scanning electron microscope (SEM). The results showed severe flash formation at stationary side related to rotating side, highly plastically deformed zone (HPDZ) was revealed at the interface with large dimension of 110 µm. Maximum microhardness values were recorded at welded center and increased from peripheral to central zones. Reducing ratio of ultimate tensile strength (UTS) and ductility for welded joint related to AISI 304 were 86 and 67%, respectively. Tensile fractures occurred adjacent to the interface at thermo-mechanically affected zone (TMAZ). Fracture morphologies by SEM were discovered cleavage features and mostly ductile mode with micro-porosities of different forms and dimensions

Concept of forge application under effect of friction time for AISI 316 using friction welding process

Present study describes the effect of forge application under consideration of friction time on metallurgical and mechanical properties of friction welded joint for AISI 316. Direct drive friction welding (DDFW) has been utilized to obtain welded joints. Three friction times (6.5 s, 8.5 s and 10 s) with two directions for this study were used; the first direction was achieved by forge phase elimination and the second was performed under forge phase application. Macro-microstructure for welded joint, microhardness across the axial direction, tensile tests and tensile fracture morphology were investigated. As a conclusion, flash formation was decreased about 30% without forge compared to forge application. Thermo-mechanically affected zone (TMAZ) was extended in 8 mm at the interface without forge and highly plastically deformed zone (HPDZ) can be found at the interface after forge application. At shorter friction time for the two directions, ultimate tensile strength (UTS) and ductility were revealed closer to AISI 316. Hence, all tensile fractures were occurred adjacent to the interface at TMAZ, except in the shorter friction time after in forge application, the fracture was happened at the base metal, and that was confirmed with the fracture morphology which has the same character of AISI 316.

Experimental study on the effect of silver, nickel and chromium interlayers and upset pressure in joining SS304L-AA6063 alloys through direct drive friction welding process

Joining of dissimilar alloys is demanded industrial applications and is effectively possible with the friction welding (FW) process. In this work, SS304L alloy rods were electroplated with silver (Ag), nickel (Ni) and chromium (Cr) and joined with AA6063 at various upset pressures (UP) (18, 21, 24 MPa) through friction welding process. The interlayer produced by the electroplating process was considered as the third element between AA6063 and SS304L during the FW. The results obtained through weld microstructures, fracture images, energy-dispersive X-ray spectroscopy, tensile properties, joint efficiency, Vickers microhardness and Charpy V-notch test of the fabricated dissimilar joints are discussed here. Fracture study showed the dimple fracture. The maximum strength and axial shortening were obtained as 216 ± 8 MPa and 27 mm, respectively. Maximum joint efficiency was achieved for Cr interlayer as 105 ± 4% at 24 MPa UP, which also showed a 1.79 tensile-to-yield (TS/YS) ratio. UP of 24 MPa improved ductile nature of joint. Ag and Ni joints rendered poor elongation. FW of chromium-electroplated specimen gave maximum weld performance than that of others. Ag interlayer at 18 MPa UP showed good hardness. Maximum impact energy observed by Cr at 24 MPa UP was 35 J. The novelty of the work is to frictionally weld the dissimilar metals of ϕ12 mm rods with Ag, Ni, Cr interlayer at welding pressures in view of safety and energy consumption. There were the changes in the microstructure and mechanical properties of joints when the interlayers, UPs changed.

Numerical simulation of plastic deformation in direct-drive friction welding of AISI 4140 and ASTM A106 steel tubes

Direct-drive friction welding of ASTM A106 and AISI 4140 steel tubes has been investigated both experimentally and numerically. A remeshing technique was implemented to accurately simulate highly distorted flashes during the FE simulation. The results revealed that the circumferential thermal expansion led to a higher contact pressure at the inner diameter of the interface and consequently, inner flashes were formed up to 18% larger than the outer ones. The maximum temperature was also located at the outer diameter of the interface in the first moments of the process, then it moved towards the center of the section where there was a balance between the higher slipping rate at the outer section and greater pressure at the inner section of the joint. Validation tests showed the capability of the FE model in terms of temperature, flash cross-section, and axial shortening with the maximum difference of 18.6%.

Friction welding of AISI 304: effect of friction time on micro-structure, micro-hardness and tension-compression properties

During direct drive friction welding could relatively predicting the micro-structural and mechanical properties of friction-welded joints by controlling the welding conditions; friction time is an important coefficient that effects on these properties, present study focused on the effect of that time on micro-structural and mechanical phenomena during that process. The process achieved in different friction time, while welding joints investigated by macroscope, microstructure, scanning electron microscope, tensile, compression and micro-hardness tests. The micro-hardness tests were performd along the interface and axial direction. Thus, the tensile tests carried out on the standardized test piece with effective diameter of 6 mm and compression tests were extracted at welded center in three angles of 0°, 45° and 90° with test specimen of 4 mm diameter and 6.5 mm length. The results showed that with increasing friction time could be found hard zone at the interface of welded joint because of extended of high plastically deformation zone, which will responsible on decreasing some useful mechanical properties such as ultimate tensile strength and yield compression strength. However, tensile fracture position occurred adjacent to the interface at the thermo-mechanical deformation zone in the rotating side for all welding pieces, where the micro-hardness attenuated at that region.

Process evaluation and optimisation of friction welding parameters on aluminium grade 6061 by direct drive friction welding method

Process evaluation and optimisation of friction welding parameters on aluminium grade 6061 by direct drive friction welding method

Process evaluation and optimisation of friction welding parameters on aluminium grade 6061 by direct drive friction welding method

The expansion of joining processes is very essential in the field of manufacturing to satisfy the industrial needs and customer expectations. Friction welding processes is one of the solid-state welding processes in which similar/dissimilar materials are joined without the use of filler materials. In this experimental investigation, aluminium grade 6061 is used as the test specimen for the welding process because of its wide variety of applications in manufacturing and automobile industries. In this research work, a radial drilling machine is used for joining the similar combination materials of aluminium grade 6061. The input process parameters such as specimen diameter, upset time and spindle speed are used to evaluate the output response like axial shortening, hardness and impact strength. The input process parameters are selected and investigated using the Taguchi design of experiments (DoEs) method based on L9 orthogonal array and particle swarm optimisation (PSO) techniques. The major plan of this investigational work is to optimise the friction welding process parameters on axial shortening, impact strength and hardness of the friction bonded specimen.

Direct drive friction welding effect on mechanical and electrochemical characteristics of titanium stabilized austenitic stainless steel (AISI 321) research reactor thick tube

Well known for its good weldability by conventional welding techniques and also for its strain hardening ability, titanium stabilized austenitic stainless steel (AISI 321) thick tube in a nuclear research reactor was subjected to direct drive friction welding. The mechanical and electrochemical behavior of the welded material was investigated. Four heat diffusion times’ effects on mechanical properties were experimentally investigated by hardness tests and tensile tests using wide and narrow gauge length extensometers for local and global measures. A generally hardened structure was produced in all heat conditions, and the micro-hardness profiles showed increased hardness variation at the weld zone. Best results, with regard to base metal ductility, were found at medium heat input (friction time 8.5 s), over which the ductility relapsed. The recrystallized zone, the thermo-mechanical affected zone and the heat affected zone X-Ray diffraction examinations revealed martensitic evolution occurrence, suggesting induced martensite formation during the welding operation. This can partially explain the hardness profile obtained. Light optical microscopy and scanning electron microscopy were used to analyze welded zones microstructures and tensile fractures morphologies. Electrochemical tests in 3.5 wt% NaCl solutions revealed improved resistance of the weld joint which can be explained by the fine structure observed in this region of the welded material. Nearby the welding area, the material exhibited straight selective inclined paths of pitting attacks.

Thermomechanical Modelling of Direct-Drive Friction Welding Applying a Thermal Pseudo Mechanical Model for the Generation of Heat

In the present work a 2D axisymmetric thermomechanical model of the direct-drive friction welding process is developed, taking the temperature dependent shear yield stress into account in the description of the heat generation, utilizing a recent thermal pseudo mechanical model originally developed for the friction stir welding (FSW) process. The model is implemented in ABAQUS/Explicit via a subroutine. The application in this case is joining of austenitic stainless steel rods with an outer diameter of 112 mm, used for manufacturing of exhaust gas valves for large two stroke marine engines. The material properties in terms of the temperature dependent flow stress curves used both in the thermal and the mechanical constitutive description are extracted from compression tests performed between 20 °C and 1200°C on a Gleeble 1500 thermomechanical simulator. Comparison between measured and simulated transient temperatures shows relatively good agreement and furthermore, the simulated deformations in terms of upsetting length and flash formation are also in good agreement with the observations from the experiment.

Rotary friction welding of molybdenum components

Joining of TZM components by inertia rotary friction (IFW) welding is an established industrial process for welding cross-sections up to 1500 mm2. Up-scaling to medium-size components up to 5000 mm2 in a direct drive friction welding process requires a better understanding of the influencing factors of the weld procedure, e.g. machine parameters, weld preforms, and the clamping system. Based on the existing IFW process for TZM tubes, welding parameters were transferred to tubular components of pure molybdenum (OD: 150 mm, ID: 130 mm, 4400 mm2). Successful welds were produced showing a fine-grained, defect-free microstructure. However, molybdenum proved to be more challenging than TZM. Particularly high upset rates and motor overload occurred during the friction phase. Therefore, a study was carried out to reveal the underlying mechanisms with small-size samples under laboratory conditions. It was shown that extensive plastic deformation of the entire weld zone occurred due to higher thermal diffusivity and lower strength of molybdenum compared to TZM. This high upset rate reduces the process window for a reproducible welding procedure significantly. In conclusion, a concentrated energy input during the transition from friction to forge phase is required to countervail the high thermal diffusivity of molybdenum. Based on these observations, the feasibility of friction welding of medium-size molybdenum tubes will be discussed.

CHARACTERISTICS OF AA7075-T6 AND AA6061-T6 FRICTION WELDED JOINTS

In this experimental study dissimilar materials of AA6061-T6 and AA7075-T6 having distinctive difference in physical and thermal properties were welded using continuous direct drive friction welding. High strength was achieved by high friction, upset pressure, low burn off length and medium rotational speed. Mechanical characterization and Micro structural behavior of the joint were given the paramount importance in this experimental analysis. The macro structure indicates that change in the direction of flow of grains perpendicular to the initial grain direction of the parent metal. Also the micro structural analysis at the interface zone showed the presence of eutectic particles that are formed as fragmented agglomerates.

A robust simulation of Direct Drive Friction Welding with a modified Carreau fluid constitutive model

The subject of this paper is the presentation of a holistic, fully-temperature-coupled simulation of Direct Drive Friction Welding (DDFW) based on the modified Carreau fluid model. The main motivation therein is the consistent and stable prediction of suitable process parameters, which is still the major problem in adopting Rotary Friction Welding (RFW) processes to new pairs of weld partners at industrial applications.The Carreau type fluid constitutive equation is derived from a Norton–Bailey law wherein the temperature dependency is accounted for by a Johnson–Cook power approach. Its main benefit is the stable and robust simulation of the process and the physical palpability of the utilized material parameters. Using a special element formulation on the general axisymmetric frame in conjunction with an Augmented Lagrange bulk viscosity term, a purely displacement based form of the numerical solution procedure is applicable. A penalty contact approach together with a regularized friction law allow for an efficient determination of the interface pressure and friction forces. The model’s performance is demonstrated by means of a test problem highlighting the potential of adopting it to industrial applications later on.

Weldability and joining characteristics of AISI 420/AISI 1020 steels using friction welding

The purpose of this study is to evaluate the welding characteristics of joints of martensitic stainless steel to medium carbon steel using friction welding. Martensitic stainless steel and commercial medium carbon steel each of 12 mm diameter were used to fabricate the joints. The friction welding tests were carried out using a direct-drive friction welding machine, which was designed and manufactured for this purpose by us. After friction welding, in order to determine the microstructural changes that occurred, the interface regions of the welded specimens were examined by means of scanning electron microscopy, X-ray diffraction and energy dispersive spectroscopy. Microhardness and tensile tests were conducted to determine the mechanical properties of the welded specimens. The experimental results indicated that martensitic stainless steel could be joined to AISI medium carbon steel using the friction welding technique and for achieving a weld with sufficient strength, the friction time has to be held as short as possible, while the rotational speed, friction and forging pressure have to be as high as possible.

A thermal and microstructure evolution model of direct-drive friction welding of plain carbon steel

A model of direct-drive friction welding has been developed, which can be used to predict the time-temperature histories, the resultant microstructure, and the microhardness distribution across the weld interface of direct-drive friction-welded AISI/SAE 1045 steel bars. Experimentally measured power and axial displacement data were used in conjunction with a finite-element transient thermal model to predict the time-temperature history within the heat-affected zone (HAZ) of the weld. This was then used with a microstructure evolution model to predict the volume fraction of the subsequent microconstituents and the microhardness distribution across the weld interface of welds produced using three significantly different welding conditions: one with optimal conditions, one with a long burn-off time, and one with high axial pressure and rotational speed but short burn-off time. There was generally good agreement between the predicted and the measured time-temperature histories, volume fraction of the resultant microstructures, and microhardness distribution in the HAZ of AISI/SAE 1045 steel friction welds produced using these three significantly different welding conditions.