Threaded Pin Profile Research Articles

Multiphysics computational modelling and experimental analysis of friction stir welding of aluminium alloy metal matrix composites (AAMMCs)

Friction stir welding is a modern method for fabricating aluminium alloy metal matrix composites (AAMMCs) that significantly enhance the properties of the parent materials. In this study, Al2O3 particles were incorporated into a 6061-T6 aluminium matrix. Experimental and numerical modeling provided in-situ observations of particle-aluminium matrix mixing in the weld stir zone (SZ). Two different pin profiles, threaded and square, were used to fabricate the AAMMC joints. The threaded pin profile resulted in uniform dispersion and a homogeneous distribution of Al2O3 particles within the aluminium matrix. In contrast, the square pin profile led to defects in the SZ and a non-homogeneous particle distribution. The volume fraction mixing of the AA6061-T6 matrix and Al2O3 at the workpiece/tool interface from top to bottom was analyzed using a level set technique. Experimental results showed effective mixing of Al2O3 particles in the AA6061-T6 matrix with the threaded pin profile, resulting in a defect-free joint, uniform particle distribution, and ultra-fine grain refinement, with grain sizes reduced to 4.19 µm. The main shear texture components observed in the threaded pin joints included B/B̅ and C, along with deformed and recrystallized texture components such as Copper {112} 〈111〉, Brass {110} 〈112〉, Goss {011} 〈100〉, Cube {001} 〈101〉, and P {011} 〈112〉 . Additionally, joints fabricated using threaded pin profiles exhibited significantly higher tensile strength (up to 270 MPa) and microhardness (average of 120 HV0.2) compared to those with square-shaped pin profiles, which showed lower values of 240 MPa and 105 HV0.2, respectively. Thus, AAMMC joints made with threaded pins demonstrate ultra-fine grain refinement, increased high-angle grain boundaries, enhanced recrystallized texture components, and improved mechanical properties, resulting in superior overall joint performance.

Multiple Response Optimization of Dissimilar Friction Stir Welding on 6061-T6 Aluminum Alloy and AZ31B Magnesium Alloy

In this paper, the optimization of the FSW tool pin profile and shoulder-to-pin ratio is carried out to achieve high tensile strength and hardness for dissimilar Al and Mg alloys. The FSW experiment with Al and Mg alloys is designed according to Taguchi's L9 orthogonal array by varying the tool pin profile and shoulder-to-pin diameter ratio. Grey relation analysis is a multiple response optimization method used to optimize the result of the experiment. The results show that the optimum tool pin profile is a cylindrical threaded pin profile tool, and the optimum shoulder-to-pin diameter ratio is 3. The maximum tensile strength, yield strength and hardness achieved in this experiment is 147 MPa, 139 MPa, and 96 HV respectively.

Insights into the friction stir processing of fused filament fabricated polymers with multiple reinforcements

ABSTRACT Friction stir processing (FSP) is a most widely used severe plastic deformation (SPD) technique used for enhancement of mechanical properties and refinement of microstructure in metals, alloys and also in surface alteration, surface composites, and metal matrix composites. This work deals with the integration of FSP with fused filament fabrication (FFF), a popular additive manufacturing (AM) method. The research work comprises of four parts, first being 3d printing of poly lactic acid (PLA) and acrylonitrile butadiene styrene (ABS) parts through FFF, then multiple reinforcements like multi-walled carbon nanotubes (MWCNTs), aluminum oxide (Al2O3) and silicon dioxide (SiO2) are filled into the grooves, then in the third step FSP is performed on the 3D specimens with variations in rotational and travel speed of the tool with threaded pin profile. Finally, tensile strength is examined and the effect of different reinforcements is studied. The results indicate that MWCNTs reinforced PLA is found to have the highest strength (37.41 MPa) which is 72.6% more than the lowest strength (21.67 MPa) obtained for SiO2 reinforced PLA. However, in the case of other polymer, SiO2 reinforced ABS exhibited maximum strength (14.71 MPa) amongst other reinforcements for ABS. The ductility is decreased for all the FFF specimens after FSP and PLA composites exhibited improved surface profiling parameters as compared with ABS composites after FSP. Also, fractography is performed to understand the failure modes of specimens filled with different reinforcements.

Influence of tool pin profile on material flow, mechanical properties and corrosion behavior of friction stir welded dissimilar Al5083-6061

In the current investigation, dissimilar aluminum alloys (6 mm thick Al5083 and Al6061) joints were friction stir welded by three different kinds of tool geometries with varied pin features. The results indicated that the formation of the onion ring was confined to a small part of the stir region in the case of triangular pin profile (TP) and square pin profile (SP), whereas the whole stir zone was covered by onion ring or banded structure in case of taper threaded pin profile (TTP). TP and SP show better pulsating action and result in better shearing of the material, causing the material to mix in sideward directions from the advancing side to the retreating side. But, the essential upward and downward material flow to obtain uniform mixing of both base materials were observed in TTP. It contributed to better material flow, and the tool achieved better mechanical and corrosion properties. The hardness values of the joints welded with TP and SP showed uneven distribution in the stir zone, and using TTP could minimize the deviation in hardness values. The role of different tool geometries on material flow, microstructure, corrosion, and mechanical behavior was studied, and the result has been reported and described with detailed analysis.

Microstructural and sensor data analysis of friction stir processing in fabricating Al6061 surface composites

Aluminium alloys, having high strength, ductility, and toughness, are useful structural materials. Composites of these with ceramic reinforcements improve the hardness and wear-resistance, making them suitable for use in the aerospace and automobile industries. Since surface properties play a crucial role for most applications, the manufacturing of surface composites of aluminum alloys is recommended. For this purpose, friction stir processing (FSP) is being utilized nowadays. It refines the microstructure with a homogeneous dispersion of reinforcements into the matrix and improves physical characteristics like surface hardness, wear resistance, strength, etc, while retaining the original characteristics of remaining volume. The study aims to investigate and compare the temperature and vibration sensor data while manufacturing Al6061 surface hybrid composites by using FSP tools with different geometries. The FSP method is utilised for the fabrication of the composites with the copper and graphite powders mixture (1:1), reinforced into the matrix surface by using two H13 tools with two different pin profiles - threaded cylindrical and plain cylindrical. Holes of different diameters and depths are drilled on the Al6061 matrix for reinforcement addition. This FSP process is investigated using a thermal gun and a Cross-Domain Development kit for temperature and vibration measurement. The variation in the vibration signals occurring on the composite workpiece during the entire process with the temperature measurements at equal intervals, is obtained. It is found that both the temperature and vibration amplitudes (400 °C and 1111Hz) are lower in the composites fabricated by FSP tool with threaded pin profile than that by FSP tool with plain pin profile (455 °C and 1305 Hz). Also, the processed samples are investigated for the microstructure by Field Emission Scanning Electron Microscope and Energy-Dispersive x-ray Spectroscopy tests. It is found that the reinforcements are dispersed more uniformly and much reduced in size (0.5482 μm) when prepared by the FSP tool with threaded cylindrical pin, while these particles are heterogeneously dispersed and less reduced in size (1.11 μm) when processes by the FSP tool with plain cylindrical pin. This research can be used to further monitor and control properties like temperature, vibration, force, current, etc, to obtain a uniform reinforcement dispersion with improved mechanical properties during the surface composite preparation by FSP.

Effect of tool pin shapes on microstructure and mechanical behaviour of friction stir welding of dissimilar aluminium alloys

The mechanical and microstructure characterizations of friction stir welding (FSW) joints of 5052-H32 with 6061-T6 aluminium alloys (AA) were investigated in this research. With two distinct tools (Taper cylinder and Threaded cylinder), the microstructural change associated to the mechanical characteristics of an FSW of dissimilar AA has been investigated under constant welding conditions such as welding speed (WS) and tool rotation speed (TRS) are 60 mm/min and 900 rpm respectively. For instance, in the hardness profile, the lesser values were obtained in the AA6061 alloy. The maximum and minimum weld joint strength were approximately 165.84 MPa and 133.85 MPa from the FSW, showed lower strength than the base material. The highest joint Efficiency of the dissimilar weld was 78.37 %, and the maximum hardness is 71 HV obtained. The defect-free stir zone development and grain size strengthening were credited with it as well. The elongations of the welded joints were measured to be 11.6 % and 7.2 %. It was discovered that using a tool with a taper pin profile and a threaded pin profile produced a joint with better tensile strength, a larger nugget area, and a smoother surface finish. Finally, it was discovered that a fine grain microstructure created by using a taper pin profile resulted in stronger welded connections compared with threaded pin profile.

Investigation on the effect of process parameters on mechanical and microstructural properties of AA8011 similar FSW weld joints

Friction stir welding (FSW) factors significantly impact the welding characteristics of AA 8011 and similar alloys weld joints produced by FSW. The tool pin profiles influence joint characteristics, weld quality, and joint strength. This study used three tool pin profiles to create weld connections at three different tool rotation rates and various welding speeds. Design of experiments (DOE) was utilized to execute complete full factorial experiments. The welded joints’ mechanical characteristics were examined using hardness and tensile tests at room temperature. The average maximum hardness number was 38.28 HRB with the tapered tool at 1300 rpm spindle speed and welding speed of 20 mm/min at 5 kN unvarying axial force of the whole operation. The lowest hardness value was 30 HRB using a taper threaded pin profile tool, rotating at 1200 rpm and welding at 60 mm/min. When the taper pin profile tool was used at 1500 rpm, the highest tensile strength of the weld joint was achieved, which was the closest value of the parent material. At the same welding speed of 20 mm/min, the taper threaded pin tool at 1300 rpm produces the lowest tensile strength of 84.16 MPa, made utilizing a taper threaded pin tool.

Fabrication of FSW Tool Pins Through Turning of H13 Tool Steel: A Comparative Analysis for Residual Stresses

In the present research, measurement of residual stress induced during turning and threading operations for the fabrication of two types of pin profiled friction stir processing/welding (FSP/FSW) tools, i.e. cylindrical profiled pin tool and cylindrical threaded profiled pin tool, is being dealt with. Workpiece was chosen to be H13 tool steel with a diameter of 22[Formula: see text]mm and 110[Formula: see text]mm length. Turning and threading was done on CNC machine tools using CNMG 12404-THM uncoated tungsten carbide cutting tool. For residual stress measurement of the workpieces, an XRD-based Pulsetec[Formula: see text]-X360n portable residual stress analyzer setup was used. The experimental results show that the cylindrical pin profile tool had a compressive residual stress of [Formula: see text][Formula: see text]MPa and compressive residual shear stress of [Formula: see text][Formula: see text]MPa, while the cylindrical threaded pin profile tool had a compressive residual stress of [Formula: see text][Formula: see text]MPa (51.8% more) and compressive residual shear stress of [Formula: see text][Formula: see text]MPa (40% less). It has been concluded that due to threading operation on the cylindrical threaded pin profile, the value of residual stress is more in it, and since the stress is compressive in nature, it would have a better positive impact while doing FSP/FSW than that of the cylindrical profiled pin tool.

Effects of threaded pin profile on torque, power, and energy by modeling and experimental analysis

Currently, the environmental care is a mainstay in the development of new technologies for the engineering industry. In welding/joining category, in the technique by friction stir, the torque analysis is vital for the efficiency, cost, power, and environmental impact of the process. However, there are few models in the literature to describe the effects of one of the most common tool pin profile on torque, power, and energy. The purpose of this paper is to study the influence of a threaded pin profile on torque, in the tool penetration and welding phases, by means of the adjustment of mechanistic models and experimental analysis. The models are used to analyze the influence of a threaded pin on power and energy demanded in the process. Experimental torque measures are also analyzed and used to adjust, calibrate, and validate the models. The results show that the use of threaded pin with a proper selection of the welding parameters can reduce the torque, power, and energy demand, with beneficial consequences on environmental impact.

Effect of tool geometry on microstructure and mechanical properties of submerged friction stir processed AA6082/AA8011 joints

This paper reports on the influence of the pin profile towards the microstructure and the mechanical properties of the underwater friction stir processed dissimilar (SFSP) AA6082/AA8011 joint. The friction stir processed (processed) dissimilar joints were initially produced through the friction stir welding technique. The SFSP joint produced using two different pin profiles were studied comparatively. The cylindrical threaded pin profile (TP1) and triangular pin profile with flutes (TP2) were used in performing SFSP on AA6082/AA8011 dissimilar joint. The joint produced using with TP2 pin profile had finer grains compared to the joint produced using the TP1 pin profile. The tensile properties of the joint produced with TP2 were higher compared to those produced using TP1.

Influence of Tool Pin Profile on Mechanical Properties and Microstructure of Friction Stir Welded Aluminium AA7075 Alloy

The present investigation describes the effect of different tool pin profiles on microstructure and mechanical properties of friction stir welded aluminium AA-7075 alloy. The tool pin profiles namely taper cylindrical threaded (TT), cylindrical (CT), square (SQ), triangular (TR), pentagonal (PT), hexagonal (HX) with constant shoulder diameter have been selected to make joints. The friction stir welding was done at constant tool rotational speed and traverse speed. From this study, it is noted that the weld joints prepared using taper cylindrical threaded pin profile exhibited good mechanical properties when compared to other pin profiles. It is due to more surface contact of tool pin and production of equiaxed fine grain structure in the weld region.

Post corrosion tensile strength and failure of dissimilar friction stir welded aluminium alloys

The present study efforts towards appraising the effects of corrosion on the tensile and fracture behaviour of dissimilar friction stir welding (FSW) of aluminium alloys. Three different dissimilar FSW joints obtained between AA6061-T6 and AA7075-T651, AA6061-T6 and AA2014-T6, AA7075-T651 and AA2014-T6, using threaded pin profile with three flat faces (TIF) tool at rotational speed of 1200 rpm and welding speed of 98 mm/min. The maximum joint tensile strength was achieved for AA7075-AA2014 joints followed by AA6061-AA2014 and least recorded for AA6061-AA7075 for as obtained FSW joints (non-corroded). The joints are further immersed into a corrosive solution for 1, 2, 7 and 14 days duration. The corrosion occurred all over the joint but much accelerated rate of exfoliation corrosion exists away from stir zone near the confluence of heat affected zone and base material irrespective of the advancing or retreating side. With increase in corrosion time the location of tensile failure shifted towards corroded region (AA6061-T6) instead of stir zone in dissimilar weld joint AA6061-AA2014, whereas it remained unchanged for other two joints. The fractured surfaces of AA6061-AA2014 FSW joints reveals the articulated view of pits and fracture morphology advocating the loss in YS, UTS and % elongation with increases in immersion duration.

FAILURE ANALYSIS AND PROCESS PARAMETER INFLUENCE ON MECHANICAL AND METALLURGICAL BEHAVIOR OF FRICTION STIR WELDED AA2219-T87 JOINTS

Friction Stir Welding (FSW) was carried out on AA2219-T87 alloy plates with various process parameters. Multiparametric optimization was carried out using Taguchi-Grey Relational Analysis (T-GRA) to determine the most influencing factors on the responses like Ultimate Tensile Strength (UTS) and Yield strength (YS) of AA2219-T87 butt joints. In this work, defect-free welding parameters were selected from the wide range of trial and L18 Taguchi Mixed factorial design was fit to further optimize the parameters by T-GRA techniques. Parameters like tool rotational speed, welding speed and tool profile were varied, tool tilt angle and thrust force were kept constant. The macro and microstructures were examined to correlate with tensile, yield and hardness property to analyze the predominant factor that would improve joint efficiency. Finer grains were found in nuggets when compared to other zones and the grain size was found to decrease from top to bottom due to centrifugal action. Scanning Electron Microscopy (SEM) studies were carried out on fracture tensile specimen to determine the mode of fracture in the different regions. EDS elemental mapping was done in fracture region of the tensile specimen and it was encountered that crack initiation is along the copper-enriched region. Tensile strength was reported to be 73% of the parent metal and optimized parameter combination was observed for tool with taper threaded pin profile that enhances metal flow.

Analysis of grain refining and subsequent coarsening along on adjacent zone of friction stir welded armour grade aluminium alloy joints

This research article presents the metallography characteristics and mechanical behavior of eco-friendly friction stir welded heavy thick rolled aluminium alloy. The travel speed and pin rotational speeds were 25 mm min−1 and 250 rpm. For this investigation tapered threaded pin profile were used for this metal joining with dimensions of (12 × 36 × 11.6) mm. Evaluated mechanical properties of tensile and microhardness values of nugget zone has been compared with parent aluminium alloy also correlated with microstructure. The metallurgical characteristic of microstructural topographies was examined optical microscopy. The fracture surface morphology has revealed of smooth and notch tensile specimen was using a secondary electron detector by SEM. The elemental analysis has been carried out in stir zone to analyze the constitutions aid of energy dispersive spectroscopy. TEM analysis has carried out qualify and quantify the strengthening precipitates of armour grade aluminium alloy joints. The SAD patterns also used to represent the polycrystalline nature of metal as well as correlate the semi- coherent and incoherent phase formations. From the results of the armour aluminium alloy joints were an appreciably lower value than the parent metal. The transverse tensile strength value of FSW joints was found to be 70% than the base aluminium alloy.

A numerical model of pin thread effect on material flow and heat generation in shear layer during friction stir welding

A novel method is proposed to analyze the effect of pin thread on the heat generation, temperature distribution and material flow field in friction stir welding (FSW). Based on the analysis of the interaction force between the thread groove and the workpiece material, special equations are derived to describe the effect of pin thread parameters on the material flow velocity inside thread grooves. These equations are combined with a three-dimensional transient CFD model to quantitatively analyze the effect of threaded pin profile on heat transfer and material flow in FSW. The results show that the average flow velocity and the downward z-component of material flow velocity near the pin side surface for threaded pin is higher than that for unthreaded pin. For a threaded pin, heat generation near pin side is a little bit increased, the area of TMAZ (thermo-mechanically affected zone) is broadened, especially the width of TMAZ near the bottom surface of the workpiece, and the pin thread can effectively improve the material flow near the pin tip. The calculated and measured thermal cycles and TMAZ boundary match with each other. Compared with the sliding mesh method, this model is easier to ensure the numerical robustness and save computational time.

Hybrid multi-objective optimization of microstructural and mechanical properties of B4C/A356 composites fabricated by FSP using TOPSIS and modified NSGA-II

Abstract A356 alloy was used as the base metal to produce boron carbide (B4C)/A356 composites using friction stir processing (FSP). The microstructural and mechanical properties of B4C/A356 composites were optimized using artificial neural network (ANN) and non-dominated sorting genetic algorithm-II (NSGA-II). Firstly, microstructural properties of the composites fabricated in different processing conditions were investigated. Results show that FSP parameters such as rotational speed, traverse speed and tool pin profile significantly affect the size of the primary silicon (Si) particles of the base metal, as well as the dispersion quality and volume fraction of reinforcing B4C particles in the composite layer. Higher rotational to traverse speeds ratio accompanied by threaded pin profile leads to better particles distribution, finer Si particles and smaller B4C agglomerations. Secondly, hardness and tensile tests were performed to study mechanical properties of the composites. FSP changes the fracture mechanism from brittle form in the as-received metal to very ductile form in the FSPed specimens. Then, a relation between the FSP parameters and microstructural and mechanical properties of the composites was established using ANN. A modified NSGA-II by incorporating diversity preserving mechanism called the ɛ elimination algorithm was employed to obtain the Pareto-optimal set of FSP parameters.

Finite element modeling of aluminum alloy AA5083-O friction stir welding process

The temperature distribution and the residual thermal stresses generated from friction stir welding process were predicted by using finite element analysis (FEA). The predicted temperature was validated experimentally by using infra-red thermal image camera. Different AA5083-O joints were friction stir welded using cylindrical threaded pin profile and tapered smooth one at different rotational and welding speeds. The increase of welding speed values resulted in lower peak temperature during the welding process and the increase of rotational speed caused higher welding peak temperature. Defect-free welds were obtained by using a threaded pin at lower rotational speed (i.e.400rpm). All the welded joints by the tapered tool pin profile had internal defects at all welding conditions. The maximum tensile strength of 230MPa was obtained by using the threaded tool at 400rpm, 50mm/min while; the minimum one of 85MPa was obtained by using the tapered tool at 630rpm, 100mm/min.

Effect of tool pin profile on distribution of reinforcement particles during friction stir processing of B4C/aluminum composites

Boron carbide /aluminum composites have been produced on an aluminum–silicon cast alloy using friction stir processing. Effect of pin profile on the distribution of boron carbide in the stir zone of the friction stir processed specimens was investigated experimentally and numerically. The material flow generated by the threaded and circular tool pin profiles, being the main reason for the distribution of particles in the metal matrix, was numerically modeled using a thermomechanically coupled three-dimensional finite element model. Numerical and experimental results show that threaded pin profile produces a more uniform distribution of B4Cp than other pin profiles. Hardness tests were performed in order to investigate mechanical properties of the composites. Wear resistance of the composite was evaluated and obtained results showed that the hardness and wear resistance of the composite significantly improved.

Effect of Double Shoulder Tool Rotational Speed on Thermo-Physical Characteristics of Friction Stir Welded 16mm Thick Nylon6

Friction stir welding (FSW) of polymers is relatively a new concept among modern polymer joining techniques. This study demonstrates the applicability of FSW on 16mm thick nylon-6 plates at constant welding rate of 25mm/min and varying rotational speed between 300 to 1000RPM. A special designed tool was fabricated which has double shoulder and right-hand threaded pin profile. It has shown excellent results at relatively lower rotation speeds. Visual inspection and microstructural examination of cross sections showed that the cavities and tunnel defects appeared only at higher rotational speeds. A linear relationship was observed between temperature and rotation speed.

Parameters optimization in FSW of polypropylene based on RSM

Purpose – The purpose of this paper is to weld polypropylene (PP) material by friction stir welding (FSW) process. The input process parameters considered were: tool pin profile, feed rate and tool rotational speed and the process output characteristics were tensile strength, Shore-D hardness, Rockwell hardness, Izod strength, Charpy strength and nugget area. Design/methodology/approach – Optimization of process parameters were carried out based on response surface methodology (RSM) and significant parameters were obtained by performing analysis of variance (ANOVA). Findings – The optimized results were the threaded pin profile for feed of 60 mm/min and tool rotational speed of 1,500 rpm. A confirmation test was carried out to verify the optimized results. Originality/value – In this paper, the process parameters were optimized based on RSM. This is newly adopted optimization techniques in the FSW process of PP materials and also it gives better results.