Continuous Drive Friction Welding Research Articles

Enhancing the Friction Welding on Cast\SIC Composites

Investigation and feasibility of continuous drive friction welding of composite materials having different combination (3%, 6% and 9%) of Silicon Carbide was done. The homogeneous distribution between two mating parts and heat affected zone of Fully Deformed Region (FD), Partially Deformed Region (PD), Undeformed Region (UD) was analyzed by using Scanning Electron Microscope. After casting homogeneous distribution analysis was done by optical microscope. Vickers hardness testing was conducted at Welded area and Unwelded area of different combination of Silicon Carbide. Mechanical properties like tensile strength were also measured. It was found that, 9% Silicon Carbide reinforced particle strength and its hardness was increased in Al7075 matrix.

Interfacial microstructures and mechanical properties of friction welded Al/steel dissimilar joints

A quality joining of Al alloy to steel is difficult to be obtained by fusion welding processes owing to the large difference between melting temperatures and the formation of thick brittle Al/Fe intermetallic compounds (IMCs) layer at the joint interface. In this study, the 6061 Al alloy and 304 austenitic stainless steel were successfully joined by the continuous drive friction welding under different welding parameters. A sound welded joint with joint efficiency of 88 % and bending angle of 80° was obtained at a low friction time and a high upset pressure, where no detect was found at the interface. The IMCs layer was not formed at the interface, but a thin diffusion zone could be observed, indicating the realization of the metallurgical bonding. Under experimental range, a relatively thinner diffusion zone was recommended to ensure higher joint strength and more excellent bend ductility. The IMCs were identified as Fe2Al5, Fe4Al13 and FeAl2 at fracture surface by XRD. The propagation of cracks during tensile testing concentrated on the area where the IMCs existed. The less amount of IMCs was detrimental for joint properties at a low welding parameters. Fracture analysis showed that the dimple fracture predominated the fracture mode for a sound joint.

Numerical and experimental investigation on friction welding of austenite stainless steel and middle carbon steel

A numerical simulation with an axisymmetric coupled thermo-mechanical model has been performed for analyzing the heat transfer and plastic deformation in continuous drive friction welding (CDFW) of 1045 carbon steel and 304 stainless steel. The simulated results shows that higher temperature and lower stress distribute in the surrounding heat affected zone at the side of 304 stainless steel. The interfacial temperature shows an increasing trend from center to periphery, indicating the non-uniformity of temperature distribution along the interface. Larger deformation amount of carbon steel is attributed to the low high temperature strength. During process, a larger temperature gradient close to the interface initially appears at 304 stainless steel side and subsequently appears at 1045 carbon steel side, owing to more heat flowing out from interface with extrusion of softened metals. Comparisons of the numerical and experimental results suggest that the developed mode can be effectively used to predict the temperature and deformation in dissimilar steels CDFW. Based on the developed model, the influences of welding parameters on the temperature and deformation variables in dissimilar steels CDFW are investigated systemically. Finally, the microstructure of the actual welded joint is investigated experimentally.

Microstructure and properties of friction welding joint of Ti–45Al-8.5Nb-0. 2W-0. 2B-0. 02Y alloy

High Nb containing TiAl alloys have prospect to be used for turbo wheel and exhaust valve for vehicle engine. Friction welding is a suitable process for fabricating these components. For investigating the weldability of these alloys, cylindrical samples of Ti–45Al-8.5Nb-0.2W-0.2B-0.02Y (in at%) alloy with a diameter of 10 mm were welded by continuous drive friction welding process, and the microstructures and the mechanical properties of the joints were analyzed in this paper. The results showed that the weldability of the present alloy was very good. At parameters of rotational speed of 2400 r/min, friction pressure of 320 MPa, burn-off distance of 3 mm and upset pressure of 360 MPa, completely metallurgical bonding interfaces were obtained. The joint had a severely plastic deformation zone (SPDZ) with a biconcave lens geometry. The thicknesses of the center and periphery of SPDZ were about 40 μm and 800 μm, respectively. There existed a transition zone (TZ) between parent metal (PM) and SPDZ. SPDZ exhibited the deformation flow lines and had a randomly-oriented recrystallized duplex (DP) microstructure with the average grain size of 2.5 μm, in contrast, PM presented a nearly lamellar (NL) microstructure with a colony size of 150 μm. TZ showed a mixture microstructure combining deformed lamellar colonies and partially recrystallized grains. At room temperature, 750 °C and 800 °C, welding joints had better tensile properties than PM.

The thermodynamic analytical models for steady-state of continuous drive friction welding based on the maximum entropy production principle

An analytical model was developed based on the thermodynamic theory of Onsager-Ziegler maximum entropy production principle (OZ-MEPP) and the relevant dynamic laws, and used for characterizing the steady-state system of the severe plastic deformation (SPD) produced by continuous drive friction welding (CDFW) without any pre-assumed or measured response parameters. The accuracy and universality of the model were verified by the CDFW experiments of eight kinds of alloys, the results of which indicated that the model could precisely predict the temperature, axial shortening rate, welding power. Moreover, the coefficient of friction, traditionally regarded as an empirical parameter, could be forecasted too.

Anisotropic Torsion Strength of Round Bar A6061 Friction Weld Joint with Various Upset Pressures

This paper revealed anisotropic torsion strength of round bar aluminium alloys A6061 friction weld joint affected by upset force. Round bar A6061 was used for friction welding specimen with two different geometries which were the specimen with flat friction surface (without chamfer angle) and the specimen with chamfer angle of 15 degree. Continuous Drive Friction welding (CDFW) was done by applying initial friction pressure of 39 MPa and upset pressure variation of 39 MPa, 79 MPa and 119 MPa. Torsion test was done according to ASTM standard in which torsion direction was applied in the same and in the opposite direction of friction welding revolution. It was found that the higher upset pressure can give the higher torsion strength of the specimen. The specimen without chamfer angle that applied by 119 MPa of upset pressure has the maximum torsion strength of 165 MPa, with torsion loading direction is the opposite to revolution direction of friction welding process. The anisotropy of torsion strength was found in the specimen, where the torsion strength of the specimen in the opposite direction of friction welding revolution is higher than in that of specimen with the same direction as revolution direction of friction welding process. The maximum difference between torsion strength in the opposite direction of revolution of friction welding and that of specimen with the same direction of friction welding revolution is around 6% that occurred in the specimen without chamfer angle and applied by the highest upset pressure. It was thought that interaction between torsion loading direction and the microstructure of the weld joint as the result of plastic deformation due to upset pressure and revolution during CDFW process affects the existence of the anisotropic torsion strength.

Metallurgical and Mechanical Behavior of AISI 316- AISI 304 during Friction Welding Process

Present study focuses on the micro-structural and mechanical behavior effect of friction time for similar (AISI 316-AISI 316 and AISI 304-AISI 304) and dissimilar (AISI 304-AISI 316) joint during continuous drive friction welding. The welding carried out with different friction time: 6.5, 8.5 and 10 s while kept all other conditions constant. The effect of that time on the strength, structural and behavior of welded metals was investigated by Energy Dispersive Spectroscopy (EDAX), Scanning Electron Microscope (SEM), micro-hardness and tensile test. The obtained results illustrated that the friction time extended was responsible on some harmful mechanical and micro-structural properties of the welded joint. Therefore, increasing in friction time is led to reduce of Ultimate Tensile Strength (UTS), reduce of ductility, increasing in level of micro-hardness and larger HPDZ, that was clearly observed in similar joint (AISI 316-AISI 316 and AISI 304-AISI 304).

Dissimilar metals AISI 304 steel and AA 2219 aluminium alloy joining by friction welding method

Abstract Welding of dissimilar metals is very much interested in industrial applications. In dissimilar metals in particular light weight metals aluminium alloy in combination with steel is advantage in automotive and aerospace industries. Welding of aluminum alloy and steel is a great challenge because of their different thermal and metallurgical properties. In this present work the joining of dissimilar metals AISI 304 steel and AA2219 aluminium with continuous drive friction welding method is used for study. This solid state welding process can be done with minimum heat affected zone so that the properties of metals cannot change. In this method because of friction heat will generate and the metals at the interface become plasticized and it was forged to weld. The welding process was done with different process parameters, rotational speed, friction pressure, upset pressure and burn of length was selected as per the previous study. The friction time kept constant for all welding joint samples. The experimental results were analyzed by means of tensile test, Vickers micro hardness test and microstructure. The strength of the joints varied with increasing friction pressure and more influenced by upset pressure. As the friction pressure and upset pressure increases the flash increases with brittle fractures at the joint interface. The welding progresses from the outer to the inner region and the intermediate compounds are formed. The optical microscope observation and SEM analysis is done for microstructure characterization. The intermetallic compounds FeAl are observed at the inter face. The elemental composition was also analyzed by EDX technique. The solid state welding enables to join dissimilar metal combination of ferrous and non ferrous metals which are difficult in conventional fusion welding methods.

Pengaruh Waktu dan Tekanan Gesek terhadap Kekuatan Tarik Sambungan Paduan Aluminium dan Baja Karbon pada Pengelasan Gesek Continuous Drive

The objective of this research was to investigate the effect of friction time and friction pressure on the tensile strength of the joining of two dissimilar materials, aluminum alloy AA6061 and carbon steel, with continuous drive friction welding process. Variations of friction times of 5 seconds, 7 seconds, 9 seconds, and 11 seconds, at each variation of friction pressures of 24 MPa, 32 MPa, and 40 MPa. Controlled variables in this friction welding process were rotational speed of 1600 rpm, upset pressure of 79 MPa which was applied for 60 seconds and diameter of friction surface of specimens which were 15 mm. The resulting strength of the bonding were than evaluated on the basis of tensile strength. Observations of temperature change during the welding process, the distribution of Vickers hardness values around the bonds area, and micro photographs, were used as support to the analysis. The results showed that the longer friction time was applied, the higher tensile strength of the bonds would be, until it began to decrease after a certain maximum value of the tensile strength had been reached. Increased of the tensile strength of the bonding did not occur linearly due to the variation of friction pressure at 9 seconds and 11 seconds of friction time. At 5 seconds and 7 seconds of friction time, increase of friction pressure caused a linear increase of tensile strength. Higher temperatures in the welding process increased the thickness of brittle layer at the bonds boundary. The increase of the brittle layer thickness causes decrease of the tensile strength of the bonds.

Microstructural Characterization and Mechanical Properties of Friction-Welded IN718 and SS410 Dissimilar Joint

Continuous drive friction welding studies on IN718 and SS410 dissimilar combination have been investigated. The influence of friction-welded parameters on microstructure and mechanical properties was dealt in detail. Six different joints were fabricated by varying rotational speed and friction pressure, by keeping forging pressure and friction time as constant. The microstructural study revealed the formation of different zones in the weld region of the dissimilar joint. Tensile and microhardness tests were conducted in order to examine the impact of process parameters of the joint and to define the ideal welding condition. The fractography images exposed the ductile fracture mode for all the samples. The friction-welded joint fabricated with the rotational speed of 1500 rpm and frictional pressure of 189 MPa yielded higher tensile strength and hardness.

The corrosion behavior of fully deformed zone of friction welded low chromium plain carbon steel joints in optimized condition

The research article deals with the corrosion behaviors of friction welded AISI 52100 grade high carbon and low chromium steel joints. In recent decade, plain carbon steels are replaced with AISI 52100 grade steel in automotive and aerospace sectors to overcome the corrosion defects. In general, the corrosion attacks are more susceptible in joints . Therefore, in this research work, the corrosion behavior of joints was analyzed in its interface and also the relationship between continuous drive friction welding parameters and properties of weld zone are established. The joints were prepared by varying the friction welding process parameters to optimize the required number of experiments. To predict the optimum properties of fully deformed zone, the empirical relationships were developed. The grain size was measured at various zones and the corresponding properties of the joints were analyzed by using scanning electron microscope, optical microscopy, and EDAX.

Microstructures and Mechanical Properties of Al/Fe and Cu/Fe Joints by Continuous Drive Friction Welding

The dissimilar pure metals Al/Fe and Cu/Fe with different metallurgical compatibility were joined by continuous drive friction welding. The friction weldability was investigated. The microstructure of the joining interface was analyzed by scanning electron microscopy, and the chemical compositions were tested by energy‐dispersive spectroscopy. The joining strength was evaluated by tensile test, and the fracture was detected by X‐ray diffraction analysis. The results show that sound joints of Al/Fe and Cu/Fe can be obtained by continuous drive friction welding process. A discontinuous reaction layer was formed on Al/Fe interface, and no obvious reaction layer appeared on Cu/Fe interface. The tensile strength of the joints increased with increasing friction pressure, and the highest strength could reach up to 70 MPa for Al/Fe joint and 222 MPa for Cu/Fe joint. All the Al/Fe friction‐welded samples failed at the friction interface, while the Cu/Fe joint under 36 and 44 MPa friction pressure failed at Cu matrix during the tensile test.

Friction Torque and Heat Input Characteristics During Continuous Drive Friction Welding of Aluminum to Steel

Friction Torque and Heat Input Characteristics During Continuous Drive Friction Welding of Aluminum to Steel

TORSION STRENGTH OF ROUND BAR A6061 FRICTION WELD JOINT INFLUENCED BY FRICTION TIME, UPSET FORCE AND ONE-SIDE CONE GEOMETRY

ABSTRACT Effect of friction time, upset force and one-side cone geometry on torsion strength of A6061 round bar friction weld joint was studied. Round bar commercial A6061 was friction welded with initial compression force of 2.5 kN on stationary part and the rotated part had revolution speed of 1600 rpm with variation of friction time of 45, 50 and 55 minutes. In the upset stage, the variation of upset force of 5 kN, 7.5 kN and 10 kN with the same upset holding time of 110 seconds. The stationary part of the specimen had friction area with variation of cone geometry that represented with ratio of upper diameter, D 1 and lower diameter, D 2 , D 1 / D 2 . It was found friction time and the ratio of D 1 / D 2 affected torsion strength in the upset force below 10 kN. In case of the higher upset force of 10 kN, the upset force more dominant to affect torsion strength of the continuous drive friction weld (CDFW) joint. The specimen with maximum torsion strength has more precipitates in grains of microstructures compared to that of specimen with lower torsion strength. Keywords : Continuous drive friction welding, aluminum, friction time, upset force, one-sdie cone geometry, torsion strength .

Review of Experimental Investigations in Friction Welding Technique

<p>Friction welding is a solid state welding processes in which the weld is obtained by the heat generated due to forging and friction. Now a day’s eco-friendly joining of dissimilar materials is the need of the industries. The advantages of friction welding process are reduction in production time and cost saving. Friction welding is classified into two types. One type is Inertia drive friction welding and the other is Continuous drive friction welding. In continuous drive friction welding one of the work pieces is held stationary while the other is held for a certain rotating speed. The two work pieces are brought together under certain friction pressure for a<br />certain period of time known as friction time. Then, the rotation is stopped and upset pressure is applied for a certain upset time. Then, the spindle is disengaged and the component is unloaded. In Inertia drive friction welding one part is held stationary while the other is clamped in the chuck which is attached to the flywheel. The flywheel and chuck is rotated for a certain seed to store a predetermined energy. In this paper, review of friction welding on different materials and their weld ability has been discussed in brief.</p>

The constitutional liquation at the interface of Al/Mg friction welding joints

ABSTRACTConstitutional liquation occurred at the friction interface of Al/Mg joints produced by continuous drive friction welding. This paper investigated the relationship between constitutional liquation and microstructure morphology of Al/Mg joints. The intermetallic compound γ-Al12Mg17 underwent morphological transitions from submicron-size particles to island-like lamellae, then to network structure as the Al content increased. The submicron-size γ-Al12Mg17 particles precipitated along the grain boundaries of α-Mg solid solution. The Mg–Al12Mg17 divorced eutectic structure was formed. The formation mechanism of eutectic structure was studied with Al–Mg binary phase diagram and Al–Mg–Zn ternary phase diagram. The network structure was derived from dendritic structure γ-Al12Mg17. Friction pressure could improve the liquid–solid hybrid microstructure morphology at the welding interface.

Size Effects in Continuous Drive Friction Welded Spray-Compacted Hypereutectic Al-Si Alloys

Spray-compacted hypereutectic Al–Si alloy is one of the most important lightweight materials for casting components in electric vehicles. Size effects in such alloys jointed by continuous drive friction welding have been investigated by connecting the interfacial microstructure with the joint strength. The nature of phases present, the topology, and the dispersion of particles have been examined carefully. The mechanical properties of joints have been characterized by transverse tensile tests, microhardness tests, XRD residual stress measurements, and finite element simulations. Size effects on the strengthening of the joint strength and the fracture of particles have been evaluated qualitatively and quantitatively. It has been confirmed that the micromechanical strengthening, which is related to the average particle size d and proportional to d−0.5, and the residual stress together determine the joint strength. By means of the fracture-mechanical analysis, a lower and an upper limit of the particle size have been defined to assess whether a particle can be refined or not during continuous drive friction welding.

Metallurgical and mechanical properties of continuous drive friction welded copper/alumina dissimilar joints

Wettability and stress concentration are the main challenges affecting the engineering application of copper/alumina dissimilar joints. In this paper, continuous drive friction welding of copper to alumina was conducted using 2.5mm thick AA1100 aluminum as interlayer. The effects of friction pressure and friction time on the tensile strength of joints were evaluated, and the interface microstructure evolution and fracture morphologies were also analyzed. Obvious mutual diffusion occurred at the alumina/aluminum and aluminum/copper interfaces, enhancing wettability and proving metallurgical bonding. Microcracks formed in alumina base due to thermo-mechanical coupling effect in welding. As increasing friction pressure and friction time, the tensile strength increased till reaching a peak value of 35MPa, and then decreased. The optimized parameters were determined as friction pressure of 12MPa and friction time of 12s. All samples failed at the aluminum/alumina interface, leaving a pit structure on alumina base. The application of pure aluminum interlayer is essential to obtain sound copper/alumina joints by diminishing stress concentration and wetting alumina, and the optimized residual aluminum layer is about 0.47mm thick. The friction interface transferred from alumina/aluminum to inner plasticized aluminum layer, and then moved to aluminum/copper till the welding process finished.

Identification of Optimal Condition for Solid State Welding of Al/SiCp Composite using Taguchi Principles Integrated TOPSIS (TPIT) Method

Traditional fusion welding techniques generally involve melting of parent material and were found to produce poor joints with aluminium based alloys and composites. The aim of research is to study the strength related characteristics of solid state joints formed with Al/SiCp composites using continuous drive friction welding process. The dominant welding parameters included in study are frictional pressure, upset pressure, speed of rotation and burn off length. The mechanical properties such as proof stress, tensile strength and Vickers hardness are observed for various joints, formed using a L27 orthogonal array design. The optimal welding condition is sorted out using Taguchi principles integrated with technique for order of preference by similarity to ideal solution (TPIT) method, taking into account the factor interactions as well. The approach is validated through the confirmation test. ANOVA is performed to supplement the TPIT method and upset pressure is identified as the prime parameter affecting the responses. The microscopic images of fractured surfaces are also examined.

Infrared thermography for monitoring heat generation in a linear friction welding process of Ti6Al4V alloy

The increasing use of titanium alloys in a wider range of applications requires the development of new techniques and processes capable to decrease production costs and manufacturing times. In this regard welding and other joining techniques play an important role. Today, solid state friction joining processes, such as friction stir welding, friction spot welding, inertia friction welding, continuous-drive friction welding and linear friction welding (LFW), represent promising methods for part manufacturing. They allow for joining at temperature essentially below the melting point of the base materials being joined, without the addition of filler metal.However, the knowledge of temperature is essential to understand and model the phenomena involved in metal welding. A global measured value represents only a clue of the heat generation during the process; while, a deep understanding of welding thermal aspects requires temperature field measurement. This paper is focused on the use of infrared thermography applied to the linear friction welding process of Ti6Al4V alloy. The attention is concentrated on thermal field that develops on the outer wall of the two parts to be joined (i.e. heat generated in the friction zone), and on the maximum temperature that characterizes the process before and after the flash formation.