Effect Of Tool Rotation Research Articles

Improving the Industrial Efficiency of Recycling Aluminum Alloy Chips Using Friction Stir Extrusion: Thin Wires Production Process

Friction stir extrusion is one of the most promising solid-state chip recycling techniques because of its relative simplicity and high efficiency. One of the most straightforward applications for the process is the production of recycled wires to be utilized as filler material in welding or welding-based additive manufacturing processes, in order to create an industrial symbiosis link, fostering a circular economy and enhancing the technology readiness level of the process. The scalability of the process to the thin wires needed for such applications has not been investigated so far. In this paper, an experimental and numerical analysis was developed. A dedicated numerical model was first validated and then used to design the tool geometry. The effect of tool rotation and tool force on both “standard” mechanical properties, as Ultimate Tensile Strength and microhardness, and specific properties for the envisaged application, as the wrapping around reels with different radii, was investigated. The numerical model results were used to explain the influence of the process parameters on the material flow as well as on the distribution of the primary field variables, namely temperature, strain, and strain rate. Finally, the energy demand was measured, and the specific energy consumption (SEC) was evaluated. It was found that a conical shoulder surface favors the conditions for effective solid bonding. Low values of the extrusion force have detrimental effects on the wires properties as they result either in insufficient strain, or hot cracking defects. High values of extrusion force results in lower SEC, unlocking the potential of the process as symbiotic link enabler.

WITHDRAWN: Enhancing industrial applicability of aluminum alloys chips recycling through Friction Stir Extrusion: Thin wires production process

Friction Stir Extrusion is one of the most promising solid-state chip recycling techniques because of its relative simplicity and high efficiency. One of the most straightforward applications for the process is the production of recycled wires to be used as filler material in welding or welding-based additive manufacturing processes, in order to create an industrial symbiosis link, fostering a circular economy and enhancing the Technology Readiness Level (TRL) of the process. The scalability of the process to the thin wires needed for such applications has not been investigated so far. In this paper, an experimental and numerical analysis was developed. A dedicated numerical model was first validated and then used to design the tool geometry. The effect of tool rotation and tool force on both “standard” mechanical properties, as UTS and microhardness, and specific properties for the envisaged application, as the wrapping around reels with different radii, was investigated. The numerical model results were used to explain the influence of the process parameters on the distribution of the main field variables, i.e., temperature, strain, and strain rate, as well as on material flow. It was found that a conical shoulder surface favors the conditions for effective solid bonding. Low values of the extrusion force have detrimental effects on the wires properties as they result either in insufficient strain, or hot cracking defects.

Multi-response optimization and effect of tool rotation on micromachining of PMMA using an in-house developed µ-ECDM system

Poly-methyl methacrylate (PMMA) is a lightweight and transparent thermoplastic material which is commonly used as an alternative for high-cost and resilient glass. PMMA has potential applications in the fields of microfluidics because of its high strength, low weight, optical transparency, and biocompatibility. Therefore, in this study, in-depth experimentation was carried out to generate microchannels on PMMA using an in-house developed micro Electrochemical Discharge Machining (µ-ECDM) system. The µ-ECDM process parameters used for the experimentation include voltage (V), electrolyte concentration (wt%), and duty factor (DF) (%). Experiments were designed at three levels of process parameters for the parametric study. The microchannels were machined on a 2.5 mm thick PMMA workpiece using a titanium tool of diameter 0.7 mm. The optical microscope images, along with SEM images, are used to characterize the machined channels. The machining characteristics such as material removal rate (MRR), tool wear rate (TWR), channel width, surface roughness (SR), and depth of the channel were studied using the process parameters. Individual response optimization is carried out using S/N ratios, but confounding of factors at different factor level settings is observed for each response. Therefore, to overcome this problem, multi-response optimization using the JAYA algorithm coupled with the multi-attributed decision-making (MADM) R-method has been adopted for maximizing MRR and depth of the channel and minimizing TWR, channel width, and surface roughness at single factor level settings. The optimal process parameters are obtained by multi-response optimization are 51 V, 24 wt%, and 55% DF, and the MRR, TWR, channel width, surface roughness, and depth of the channel are found to be 21.5 µg/min, 5.5 µg/min and 804.33 µm, 5.2412 µm, and 238.22 µm, respectively that are in close pact with the predicted observations. Further, the optimal machining parameters have been used along with tool rotation (in RPM) to observe the effect on machining features. The findings show that with increment in tool rotation rate improved the MRR, TWR, and depth of the channel decreased the channel width and surface roughness.

Numerical Simulation of the Thermo-Mechanical Behavior of 6061 Aluminum Alloy during Friction-Stir Welding

In this work, a finite-element model was elaborated to simulate the thermomechanical behavior of 6061 aluminum alloy during friction-stir welding (FSW). It was shown that FSW-induced deformation is a two-stage process. In addition to the stirring action exerted by the rotating tool probe, the material in the near-surface area of the stir zone also experienced a secondary deformation by the shoulder edge after passage of the welding tool. Both deformation steps were found to be comparable in terms of temperature and strain, but the secondary deformation was primarily concentrated in the near-surface layer. The effects of tool rotation and translation rates on FSW temperature and strain were also systematically examined. Depending on particular welding conditions, the peak welding temperature was predicted to vary from 360 to 500 °C, while the cumulative effective strain was from 12 to 45.

Mechanical behaviour of friction stir welded AA7075-T651 joints considering the effect of tool geometry and process parameters

ABSTRACT Obtaining high-strength aluminium alloy welded joints considering the effect of tool geometry and process parameters still needs attention. In this study, AA7075-T651 aluminium alloy plates were joined using friction stir welding (FSW). The mechanical behaviour of joints was investigated considering the effect of tool rotation, welding speed, and stirred pins having two different geometries (conical pin and conical threaded pin). The welded joints were characterised by their tensile strength, microhardness, microstructure, and percentage elongation. Welds exhibited superior tensile properties when conical threaded pins were used. The optimised FSW process parameters revealed higher tensile strength of 177 MPa, the microhardness of 136 HV, and surface roughness of 15 μm with the conical threaded pin at tool rotation and welding speed of 1740 rpm and 40 mm/min, respectively. No significant difference in the microhardness was observed with both tools. The highest joint efficiency and percentage elongation of 34% and 17.4% were observed with the conical threaded pin.

Strength Analysis of Friction Stir Welding (FSW) Joint Under Minimize Rotation Speed of FSW Tool

Friction stir welding (FSW) broadly used in the same grade as aluminium alloy but for aluminium alloy material it requires high speed rotation of FSW tool which develops high temperature on tool. In this paper process parameter of FSW are studied based on the strength of welding joint and predict FSW tool speed as low as possible according to the past literature. Constant machining parameters are tool rotation of FSW is 800 rpm and welding speed 15 mm/min. In this work analysing the strength variation of welding joint under two mode of pre-heating temperature on the work-piece then variation of cooling medium apply after preheating to change the grain structure of work-piece. In this work the FSW process is passed over two pieces of aluminum at once and the effect of tool rotation and temperature of the tool is discussed by preparing the sample for testing according to the ASTM dimension.

Multiphysics simulation and experimental investigation of microtool fabricated by EMM

ABSTRACT Due to the continuous demand for miniature products, demand for microtool increases. Various conventional and non-conventional methods have been employed for the fabrication of microtool. In this paper, electrochemical micromachining (EMM) is used for the fabrication of microtool as it offers good accuracy, no heat generation, contactless process, no tool wear and good surface finish. The microtool of different shape and sizes are fabricated from Tungsten tool having initial diameter of 500 µm using the two different techniques. In the first technique, the tool is placed inside the pre-made hole in stainless steel (SS) plate and the effect of tool rotation is analyzed. In the second technique, the tool is kept adjacent to SS plate and the analysis is based on the interelectrode gap (IEG) during machining. COMSOL® Multiphysics software is used to create a 2D model to study the variation of current density distribution in the interelectrode gap. First technique with tool rotation results in conical microtool with good surface finish and second technique results in cylindrical microtool with diameter less than 100 µm. Simulation results are validated with the experimental results with an error below 15%.

Effects of tool rotation and powder abrasive on EDM performance of H13 tool steel

The present work reports an experimental study on the performance of rotary electro-discharge machining (REDM) on H13 tool steel using rotary copper electrode in the presence of abrasives. Machining performance was evaluated in terms of machining rate and surface roughness. Experiments were conducted with peak current, speed of electrode rotation, concentration of abrasive and pulse on time as process variables. Taguchi methodology was adopted for experimental design. Analysis of variance (ANOVA) was performed to investigate the influence of input parameters on material removal rate (MRR) and surface roughness (SR). This work introduces a new method abrasive mixed REDM of improving machining performance vis. rotation of tool in presence of abrasives. Results indicated that giving rotation to EDM tool results in considerable improvement in MRR and SR. This method successfully removed the debris from the machining area which was one of the major challenges in the existing process and major cause of rough surface due to inactive pulses. It was confirmed experimentally that material removal rate increased by 25.53% and surface roughness decreased by 21.22%.

Effects of tool rotation and powder abrasive on EDM performance of H13 tool steel

The present work reports an experimental study on the performance of rotary electro-discharge machining (REDM) on H13 tool steel using rotary copper electrode in the presence of abrasives. Machining performance was evaluated in terms of machining rate and surface roughness. Experiments were conducted with peak current, speed of electrode rotation, concentration of abrasive and pulse on time as process variables. Taguchi methodology was adopted for experimental design. Analysis of variance (ANOVA) was performed to investigate the influence of input parameters on material removal rate (MRR) and surface roughness (SR). This work introduces a new method abrasive mixed REDM of improving machining performance vis. rotation of tool in presence of abrasives. Results indicated that giving rotation to EDM tool results in considerable improvement in MRR and SR. This method successfully removed the debris from the machining area which was one of the major challenges in the existing process and major cause of rough surface due to inactive pulses. It was confirmed experimentally that material removal rate increased by 25.53% and surface roughness decreased by 21.22%.

Effect of tool rotation in near-dry EDM process on machining characteristics of HSS

ABSTRACTRotary tool near-dry electrical discharge machining (RT-ND-EDM) is a process variant of EDM, which utilizes two phase dielectric medium instead of a conventional liquid or gaseous dielectric medium. The present work, RT-ND-EDM was investigated while machining of high speed steel (AISI M2 grade) using glycerin-air dielectric medium. The effect of various input process parameters was investigated on material removal rate (MRR), surface roughness (SR), and hole overcut (HOC). The input parameters considered were tool rotation speed, current, pulse on time, liquid flow rate, and gas pressure. Experiments were designed and conducted using response surface methodology. Regression models were also developed. The results revealed that the tool rotation speed has a significant effect on MRR, SR, and HOC. FE-SEM micrographs showed that the machined surfaces obtained by RT-ND-EDM have relatively lower micro-cracks, debris accumulation and craters. Also, deep through holes were successfully drilled in 24 mm plate using RT-ND-EDM process.

On effect of tool rotation on performance of rotary tool micro-ultrasonic machining

ABSTRACTThe present research paper is based on a comparative study of stationary tool micro-ultrasonic machining (STMUSM) and rotary tool micro-ultrasonic machining (RTMUSM). Microchannels were developed on glass work material by using both processes. The effect of tool rotation on the performance of micro-USM was investigated. The performance of both processes was compared on the basis of material removal rate (MRR) and depth of channel (DOC) as response characteristics. The power rating, work feed rate, concentration of abrasive slurry, and abrasive mesh size were chosen as variable input process parameters in this investigation. The form accuracy of the fabricated microchannels was analyzed with the help of imaging technique. Also, a qualitative analysis of tool wear was carried out with the help of microscopic images. The experimental results revealed that the tool rotation significantly improved the performance of micro-USM. The RTMUSM resulted in 155% and 147% higher MRR and DOC as compared to STMUSM. The tool wear was also found to be lesser in RTMUSM as compared to STMUSM and as a result of that form accuracy of machined microchannels improved.

Effect of process parameters on microstructural and mechanical properties of friction stir diffusion cladded ASTM A516-70 steel using 5052 Al alloy

In the present study, friction stir diffusion cladding (FSDC); a new solid-state process based on friction stir welding, was employed for cladding ASTM 516-70 steel with Al5052-H32 alloy. The effects of tool rotation and traveling speeds on microstructural and mechanical properties of the cladded system were investigated. Tool rotation speeds of 250, 500 and 1000 rpm and traveling speeds of 50, 100 and 150 mm/min were selected for evaluation at constant zero tilt angle and tool plunge depth of 2.0 mm. It is found that the combination of high rotational and high travel speeds results in lack of fill and voids on the cladded surface, while low rotational and high travel speeds result in weak bonding at the interface with disbandment of the cladding material. Similarly, surface roughness was found to increase with the tool advance per revolution (APR). Optimum properties were obtained at a combination of rotation/travel speeds of 500 rpm/50 mm/min. Specific fracture load of about 430 N/mm was found for samples with optimum process parameters.

CFD Simulation of Dielectric Fluid Flow in Micro Electro Discharge Milling Process

The complex phenomenon of sparking and melting in micro electro discharge milling process occurs at an interelectrode gap of dimension less than 50 microns. High-temperature plasma can melt practically any material and the material is removed from the gap in the form of debris particles. The behavior of fluid properties at interelectrode gap will be useful to elaborate material removal and effect of tool rotation in the micro electro discharge milling process. Based on previous reports it was observed that tool rotation is an inherent part of spark micromachining which directly influences the debris flushing and redeposition. For stable machining performance, removal of debris from the gap is important. Dielectric flow plays an important role in flushing away debris from the gap and cooling the electrode. This work investigates the fluid flow in the interelectrode gap. The fluid flow at interelectrode gap for different machining conditions is analyzed by computational fluid dynamics simulation. The simulation results were compared with scanning electron micrographs. The influence of inlet nozzle velocity, tool rotation and electrode gap on the dielectric fluid flow at the gap is investigated and the results are presented.

Experimental investigation on drilling of borosilicate glass using micro-USM with and without tool rotation: a comparative study

The application of microproducts is increasing rapidly in various fields such as automobiles, electronics, microfluidics, bio-MEMS, etc. These microproducts are generally made of hard and brittle materials, e.g., glass, quartz, ceramics and silicon, etc. The machining of these materials in micro-domain is a difficult task. Micro-ultrasonic machining (micro-USM) is a preferred process for machining of hard and brittle materials. But high tool wear and low aspect ratios limits its industrial use. This investigation compares the effect of tool rotation on material removal rate and hole overcut. Additionally, aspect ratio was measured. The variable process parameters for the investigation were power rating, static load, slurry concentration and abrasive size. Imaging was used for qualitative analysis of tool wear. The experimental results reveal that micro-USM with tool rotation resulted in higher material removal rate, lesser hole overcut, high aspect ratios and lesser tool wear in compared with micro-USM without tool rotation.

Effect of Tool Rotation on MRR, TWR, and Surface Integrity of AISI-D3 Steel using the Rotary EDM Process

Electric discharge machining (EDM) is an acclaimed non-conventional machining process that is used for machining of hard or geometrically complex and electrically conductive materials which are extremely difficult to machine by conventional methods. One of the foremost demerits of this process is its very low material removal rate (MRR). For this, researchers have proposed some modifications like; providing rotational motion to the tool or workpiece, mixing of conducting fine powders (such as SiC, Cr, Al, graphite etc.) in the dielectric, providing vibrations to either the tool or the workpiece etc.The present research examines how the MRR and tool wear rates (TWR) vary with the variation in the tool rotation speed and their effects on the surface integrity of the workpiece. The results obtained clearly indicate that the tool rotation significantly improves the average MRR up to 49%. Moreover, the average surface finish also gets improved by around 9–10% while using the rotational tool EDM. Due to the tool rotation, the recast layer thickness is less for the rotary EDM as compared with the stationary tool EDM process. Furthermore, the micro-cracking on the recast surface of the workpiece is also less for the rotary tool EDM as compared with the stationary tool EDM.

Effects of magnetic field and rotary tool on EDM performance

In this work, the effects of tool rotation and various intensities of external magnetic field on electrical discharge machining (EDM) performance have been studied. Experimental trials divided into three regimes of low energy regime, middle energy regime and high energy regime. The influences of process parameters were investigated on main outputs of material removal rate (MRR) and surface roughness (SR). In order to correlate the input parameters and output values two mathematical models were developed to predict the MRR and SR according to variations of discharge energy, magnetic field intensity and tool rotational speed. Results indicated that the applying a rotational magnetic field around the machining gap improves the MRR and SR. Combination of rotational magnetic field and rotary electrode increases the machining performance, in comparison of previous conditions. This is due to better flushing debris from machining gap. This work introduces a new method for improving the machining performance, in cost and time points of view.

A microscopic investigation of machining behavior in μED-milling process

The discussion presented in this work is about evaluation of physical behavior of μED-milling process based on channel shape, form and surface quality. μED-milling process is gaining lot of interest in recent times in micro manufacturing to generate complex shapes. Tool rotation and traverse which are not an inherent part of EDM process become important for μED-milling where it significantly influence the molten metal flow, debris flushing and redeposition. The effect of tool rotation not only disturbs the plasma but also affects the final shape and form of channel. Using scanning electron micrographs of μ-channel at different instant and conditions of machining, the physical nature of the process is understood and the results are presented. This study will provide a better understanding of the working phenomenon of μED-milling process.

Friction stir welding of aluminum alloy with varying tool geometry and process parameters

The present investigation had two objectives: first, to study the effect of the geometry of the tool pin, and second, the effect of tool rotation and welding speeds on the mechanical properties of friction stir welded joints made for samples of commercial grade aluminium alloys. The results obtained from the performed experiments showed that tools with tapered pins created superior mechanical properties for the friction stir welded joints. It was also found that overall mechanical response depended on the ratio of the tool rotation speed to the tool traverse speed. Suitable values for this ratio were isolated that lead to high quality mechanical properties for the created joints.

Thermo-Mechanical Investigations during Friction Stir Spot Welding (FSSW) of AA6082-T6

Friction Stir Spot Welding (FSSW) is a variant of the Friction Stir Welding (FSW) process and has been successfully used in industrial applications. During the FSSW process, thermal inputs due to friction and deformation are commenced simultaneously, as the non-consumable rotating tool plunges into the workpiece to be welded. Various assumptions and hypotheses for mechanisms of heat generation and material deformation during FSW/FSSW process are reported, but a consensus is still to be reached. The joining quality is mainly dependent upon the material flow in this solid state joining technique. The material flow and deformations in the near and far fields of the weld are directly affected by the temperature-sensitive mechanical properties. Therefore, a comprehension of thermo-mechanical responses are of high importance from the viewpoints of parameter optimization and understanding of the mechanisms. The FSSW process is experimentally and theoretically studied to address these issues of the mechanism of heat generation and coupled thermo-mechanical response of the workpiece, as well as the effects of tool rotation and plunge speeds. For theoretical studies, a 3-dimensional, physical-based FEM (Finite Element Method) model is developed using commercial code. For heat generation, friction and deformation-based formulations are used. For material responses, thermal and strain rate-sensitive, elastic-plastic data are employed by a constitutive Johnson Cook material model and thermo-mechanical behaviour is analyzed with respect to experimental observations. To cope with high calculation time and distortion of the mesh, built-in features of the code, mass scaling, ALE (Arbitrary Lagrangian Eulerian) and mesh re-mapping were used. As a result of this work, a basic platform in the form of a physical-based, coupled, thermo-mechanical model is developed. With the help of this model, effects of process parameters on the temperature — displacement behaviour of the workpiece are studied. The role of interaction conditions at the tool-workpiece interface is emphasized and a simplified conceptual mechanism for effects of process variables on the physical phenomena is presented.

Effects of tool rotation and pin diameter on fatigue properties of friction stir welded lap joints

The objective of this study was to determine the effects of the tool pin diameter and tool rotation on the fatigue behaviour of friction stir welded (FSW) lap joints. FSW lap joints of AA 5754 aluminium alloy plates were produced by means of a conventional semiautomatic milling machine. Consequently, defect free FSW lap joints were produced on alloy plates at a constant traverse speed but with different tool pin diameter and tool rotation. Therefore, within this study, tool rotation and the tool pin diameter were accepted as variable parameters, while others held fixed. The results of the tests performed, indicate that an optimisation is required for the studied parameters, in order to obtain reasonable fatigue strength. An index, related to tool rotation, traverse speed, pin diameter, and pin height can be identified and used to select optimum parameters for FSW applications.