Parameters Rotational Speed Research Articles

Weldability of high-density polyethylene using friction stir welding with a non-rotational shoulder tool

ABSTRACTThis work studies the weldability of high-density polyethylene (HDPE) using the process of friction stir welding (FSW), with two different tools (one conventional tool and another with a non-rotational shoulder, called non-conventional). The comparative evaluation was performed using combinations of the parameters of rotational speed (vW) and feed rate (vA), which were adjusted for each tool. Weldability was evaluated based on visual inspection of the presence of discontinuities via stereoscopy and confocal microscopy and hardness in welded joints. As a result, it was found that the use of the non-conventional tool resulted in welded joints without any discontinuities and with an excellent external appearance thanks to less heat being used. The hardness in the stir zone was lower than that of the base material, showing different behaviour on the forward and backward sides depending on the parameters of the process.

Pengaruh variasi kecepatan putar dan diameter tool terhadap sifat mekanik sambungan fssw aluminium alloy 5052 dan baja ss400

<p><em>Friction stir spot welding (FSSW) is a development from solid state welding to jointa different materials (dissimilar). Dissimilar FSSW is widely used in the automotive industry due to the advantages of joining these two materials with weight savings while exploiting the best strength. This research aims to know the effect of welding parameters of rotation speed and tool diameter on mechanical properties on dissimilar FSSW aluminum alloy 5052 and SS400 steel. Variations in rotational speed used is 800, 1250, 1600, 2000 rpm and tool diameter 10, 12, 14 mm. Plunge depth and dwell time in this research were made uniform. This research used a lap joint configuration with aluminum plate placed on the top and steel plate placed on the bottom. Physical characteristics were analyzed through observation of macro and microstructures, while mechanical characteristics through vickers hardness testing and shear tensile testing. The results indicate that the diameter of 10 mm tool and 1600 rpm rotation speed produce the highest tensile shear load value of 2.4 kN with interface fracture.</em><em></em></p>

Effect of Dwell Time and Tool Rotational Speed of Friction Stir Spot Welding on the characteristics of AA3105 joints

In the last decades of the twentieth century and the first decade of this century, the issue of rationing energy and the issue of environmental conservation has become the main concern of the company's manufacturing the means of transportation. This can be achieved using Al-alloys and other light alloys as a best alternative for steel in the bodies of the auto industry. Aluminum and light metals alloys have lower melting point and so fusion welding and resistance spot welding processes cause more changes in the properties of these alloys and lead to getting unsound welding. Solid state welding methods such as friction stir spot welding consider the best alternative. In the present work, effect of dwell time and tool rotational speed on microstructural and mechanical properties of friction spot welded joints of AA3105 alloy, was investigated experimentally. The travel speed and plunging depth were kept as constant, whereas, the dwell time and rotational speed parameters were varied with different values and their effect was investigated. Lap shear test, microhardness, and metallographic tests were performed. The results showed that, the shear strength is significantly affected with variation of the input parameters. The main findings of the present work were that high shear strength of the friction stir spot welded joints is achieved at dwell time of 7.5 s and rotational speed of 1400 rpm, as well as the highest microhardness was also achieved with this set of input parameters.

Effect of Dwell Time and Tool Rotational Speed of Friction Stir Spot Welding on the characteristics of AA3105 joints

In the last decades of the twentieth century and the first decade of this century, the issue of rationing energy and the issue of environmental conservation has become the main concern of the company's manufacturing the means of transportation. This can be achieved using Al-alloys and other light alloys as a best alternative for steel in the bodies of the auto industry. Aluminum and light metals alloys have lower melting point and so fusion welding and resistance spot welding processes cause more changes in the properties of these alloys and lead to getting unsound welding. Solid state welding methods such as friction stir spot welding consider the best alternative. In the present work, effect of dwell time and tool rotational speed on microstructural and mechanical properties of friction spot welded joints of AA3105 alloy, was investigated experimentally. The travel speed and plunging depth were kept as constant, whereas, the dwell time and rotational speed parameters were varied with different values and their effect was investigated. Lap shear test, microhardness, and metallographic tests were performed. The results showed that, the shear strength is significantly affected with variation of the input parameters. The main findings of the present work were that high shear strength of the friction stir spot welded joints is achieved at dwell time of 7.5 s and rotational speed of 1400 rpm, as well as the highest microhardness was also achieved with this set of input parameters.

Microstructure and hardness performance of AA6061 aluminium composite using friction stir processing

Rice husk ash (RHA) is an industrial waste that has become a potential reinforced material for aluminium matrix composite (AMCs) due to low cost and abundantly available resources. Friction stir processing (FSP) has been introduced as a method to modify surface properties of the metal and alloy including theirs composite as well. The present work reports the production and characterization of AA6061 and AA6061/5 vol% RHA using FSP using parameters rotation speed 1000 rpm and traversed speed 25 mm/min. The microstructure was studied using optical microscopy (OM). A homogenous dispersion of RHA particles was obtained in the composite. No agglomeration or segregation was observed. The produced composite exhibited a fine grain structure. An improvement in hardness profile was observed as AA6061/5 vol% RHA improves in hardness compared to FSPed of AA6061 without reinforcement.

Soldabilidad de Polietileno de Alta Densidad Usando Soldadura por Fricción-agitación con una Herramienta de Hombro no Rotacional

Resumen: En este trabajo se estudió la soldabilidad de polietileno de alta densidad (PEAD) mediante el proceso de soldadura por fricción agitación (SFA), usando dos herramientas diferentes, una convencional y otra con hombro no rotacional, denominada no convencional. La evaluación comparativa fue realizada bajo combinaciones de los parámetros de velocidad de rotación (vW) y velocidad de avance (vA) ajustados para cada herramienta. La soldabilidad fue valorada con base en inspección visual, la presencia de discontinuidades mediante estereoscopia y microscopia confocal y la dureza en las juntas soldadas. Como resultado se obtuvo que la herramienta no convencional permitió obtener juntas soldadas libres de discontinuidades y con excelente apariencia externa gracias al menor calor aportado. La dureza en la zona agitada fue menor a la del material base, mostrando comportamientos diferenciados en los lados de avance y retroceso en función de los parámetros de proceso.

Facile and Cost-Effective Synthesis and Deposition of a YBCO Superconductor on Copper Substrates by High-Energy Ball Milling

The article investigates the synthesis and deposition of YBCO on a copper substrate for various functional purposes. The superconductor is first prepared by mechanically alloying elemental components (yttrium, barium, and copper) for 50 hours in a high-energy ball mill with subsequent protocol of heat treatment in an oxygen-rich atmosphere to arrive at stoichiometric ratios of YBa2Cu3O7. The material is then deposited on a thin copper substrate also by ball milling under various parameters of rotational speed and deposition time to select the best and most homogenous substrate coverage. Atomic force microscopy has confirmed the desired results, and other microstructural, thermal, and electrical techniques are used to characterize the obtained material. High-energy ball milling proved to be a versatile means to synthesize and deposit the material in a straightforward manner and controllable parameters for different deposit thicknesses and coverages.

Multi Response Optimization of Process Parameters on AA8011 Friction Stir Welded Aluminium Alloys Using RSM Based GRA Coupled with DEA

The friction stir welding process is the newly developed material joining process used to join the different materials which are very difficult to join in the conventional fusion welding process. In this investigation using the specially designed straight cam profiled tool, the multiple responses of Ultimate tensile strength, Ultimate yield strength and Percentage of elongation with the process parameters of rotational speed, tool tilt angle and feed rate are optimized. The five level, three factor rotatable central composite design is selected to optimize the responses of friction stir welded AA 8011 aluminium alloys. The highest gray relational grade with the highest relative efficiency is found using the gray relational analysis coupled with the data envelopment analysis to predict the optimum parameters. It exposes that at the rotational speed of 680 rpm, the tool tilt angle of 98 degrees and the feed rate of 24 mm/min the good weld quality can be attained.

Multiple Performance Characteristics Optimization for AA8011 on Friction Stir Welding by RSM Based DEA

In this investigation, the optimization of the multiple responses of Vickers hardness, Impact strength with notched and Un-notched conditions of the process parameters of rotational speed, tool tilt angle and feed rate with the straight cam profiled tool is considered. The three factors, five level rotatable central composite design are selected to optimize the responses of friction stir welded AA 8011 aluminium alloys. The highest relative efficiency is found using the data envelopment analysis to predict the optimum parameters. It reveals that at the rotational speed of 680 RPM, the tool tilt angle of 85 degrees and the feed rate of 24 mm/min the good weld quality can be achieved.

Optimization of Friction Stir Extrusion (FSE) Parameters Through Taguchi Technique

In this study, a novel friction stir extrusion (FSE) process is investigated for fabrication of fully-consolidated wires. The process parameters of rotational speed (RS), plunge rate (PR), and extrusion hole size are optimized using the Taguchi L8 orthogonal design of experiments. The optimum process parameters are determined with reference to the average grain size of the wire. The analysis of variance shows that the RS of plunge die is the most dominant factor in deciding the soundness of joint, while PR also plays a significant role. The microstructural studies reveal that initial grains of Mg ingot undergoes significant refinement in the specimens produced by the FSE process. Mechanical tests show that almost all recycled specimens can achieve higher strength and elongation than parent material at room temperature. This study shows that defect free, high quality wires can be produced using a proper combination of process parameters and recommends parameters for producing the best wire properties.

Modelling the granular flow in a rotating drum by the Eulerian finite element method

This paper presents a numerical study on the flow behaviours of granular materials in a rotating drum based on the Eulerian-formulation finite element method (Eulerian FEM). The granular material is here assumed to be cohesionless and treated as a continuum medium described by the conventional Mohr–Coulomb elastoplastic model. It is shown that this Eulerian FEM approach can reproduce almost all the particle flow patterns that frequently happen in rotating drum, i.e. slipping, slumping, rolling, cascading, cataracting and centrifuging, provided that the parameters of rotational speed, coefficient of friction and internal friction angle are properly selected. On average, the predicted surface angles of a rotating bed are comparable to the experimental observations (Parker, D.J. et al., 1997. Positron emission particle tracking studies of spherical particle motion in rotating drums. Chem. Eng. Sci. 52, 2011–2022.), but the curvature of surface may be slightly over-estimated for drums comprised by big component particles. Linear distributions of particle velocity are seen along the mid-cord of the bed and agree well with the data published in the literature (Boateng, A.A., 1998. Boundary layer modelling of granular flow in the transverse plane of a partially filled rotating cylinder. Int. J. Multiphas. Flow 24, 499–521). The bulk stress inside the particle bed is also investigated, and its spatial distribution is demonstrated to depend on the rotating speed and other operational parameters.

Material Removal Rate of Zirconia in Electro Discharge Micromachining <sup></sup>

This paper investigates the material removal rate (MRR) in electro discharge micromachining (micro-EDM) of zirconia. Experimental investigation is carried out with 800 μm diameter tungsten electrode with two varying parameters rotational speed and gap voltage. The MRR data are analyzed and an empirical model is developed using Design Expert software. The optimum parameters for maximum MRR are found to be 375 rpm rotational speed and 80 V gap voltage.

Multi Response DEA-Based Taguchi Optimization of Process Parameters on AA8011 Friction Stir Welded Aluminium Alloys

In this investigation, an attempt using data envelopment analysis based Taguchi method, is involved in solving the multi-response optimization of the process parameters of rotational speed, transverse speed, tool tilt angle with different tool pin profiles on the stir zone evolution in AA8011 Aluminium alloys. Three different tool pin profiles (hexagonal, pentagonal pin profiles of High Carbon High Chromium steel and Hexagonal tool pin profile of H13 steel) have been used to make the joints at the different combination of process parameters using L9 orthogonal array. The Vickers hardness and Impact strength are measured to optimize the process parameters using DEA based Taguchi method. It is found that the optimum conditions of rotational speed 660 RPM, transverse speed of 30 mm per minute and tilt angle of 2 degrees with the hexagonal tool pin profile of High Carbon High Chromium steel yielded a good quality weld.

A Fuzzy Logic Model for Evaluation of Oil-Film Pressure in Hydrodynamic Bearing

This study presents a new approach for evaluation of oil-film pressure in hydrodynamic bearing. Oil-film pressure is one of the critical parameter which determines the performance of hydrodynamic bearing. In this research parameters of rotational speed, bearing load and oil-feed pressure are considered as model independent variables. Modelling and simulations are done in Matlab. The research shows that as compared to other conventional techniques approximate fuzzy reasoning provides a more logical approach.

Analysis of the surface roughness obtained in a friction spinning process based on empirical models

In this paper, an new way to analyze and empirically model the surface roughness of a flange geometry after a friction spinning process is presented. The friction spinning process is an innovative incremental forming technology. This new process combines thermomechanical friction elements of the friction welding process within a conventional metal spinning process. The friction allows a self-inducted heat generation and as a consequence a defined increase of formability. It is possible to produce multifunctional, complex parts from standard tubes and sheets. The process thus readily meets the demands placed on efficiency and the manufacturability of complex lightweight components. By choosing the appropriate process parameters, e.g., axial feed rate or relative motion, the contact conditions between the tool and the workpiece can be influenced in a defined way. A further advantage is the feasibility of influencing the grain structure and the hardness in a locally defined manner. It offers the possibility to manufacture finished components with the required surface roughness. Since not all parameter settings of the parameters rotation speed, head radius, feed, and tool infeed width lead to a measurable surface of the component, a gradient boosting machine will be used as classifier for predicting the valid areas of the design space. Furthermore, the influence of the tool temperature is taken into account. For the empirical modeling of the spatial distribution of the surface roughness, methods from the design and analysis of computer experiments are employed.

Investigation of Recast Layer of Non-Conductive Ceramic due to Micro-EDM

This paper presents the investigation of minimum recast layer of zirconium oxide (ZrO2) due to micro-EDM using EDM-3 synthetic oil as dielectric fluid and tungsten as the tool electrode with control parameters of rotational speed and gap voltage. The investigation was performed using multi-process micro machine tools DT 110. The recast layer thickness was observed using scanning electron microscope and its hardness was measured using micro-Vickers hardness tester. The hardness data were analyzed and an empirical model was developed. The optimum value for minimum recast layer hardness was 873.46 Hv with rotational speed of 395 rpm and gap voltage of 110 V.

Fuzzy Logic based Model to Predict Maximum Oil-Film Pressure in Journal Bearing

Oil-film pressure response is one of the key parameters that describe the operating conditions in hydrodynamic lubrication regimes. In the present study, a fuzzy logic model is developed to predict the maximum oil-film pressure in hydrodynamic plain journal bearing. In the development of predictive model, journal bearing parameters of rotational speed, bearing load and oil-feed pressure are considered as model independent variables. For this purpose, a number of experiments, based Box-Behnken experiment Design technique (BBD), are performed to observe the maximum oil-film pressure values. The results revealed that the model is able to predict maximum oil-film pressure adequately.

Differential transformation and differential quadrature methods for centrifugally stiffened axially functionally graded tapered beams

The free bending vibration of rotating axially functionally graded (FG) Euler–Bernoulli tapered beams (ETB) with different boundary conditions are studied using Differential Transformation method (DTM) and differential quadrature element method of lowest order (DQEL). These two methods are capable of modeling any beam whose cross sectional area and moment of inertia vary along the beam. In order to verify the competency of these two methods, natural frequencies are obtained for problems by considering the effect of material non-homogeneity, taper ratio, rotating speed parameter, hub radius and tip mass. The results are tabulated and compared with the previous published results.

Free Vibration of a Functionally Graded Rotating Timoshenko Beam Using FEM

Free vibration analysis of functionally graded ordinary (FGO) and functionally graded sandwich (FGSW) rotating cantilever beam is carried out using finite element method. The properties along the thickness of FGO beam and along the thickness of the core of FGSW beam are assumed to follow power law as well as exponential law. The increase in the parameters for rotary inertia, hub radius and rotational speed, increase the first two mode frequencies of both the beams no matter how the properties vary along the thickness of beams. The effect of property distribution laws on the frequencies is found to be predominant for lower values of rotary inertia parameter and for higher values of rotational speed parameter and hub radius parameter. The first two mode frequencies of FGSW beam increase with increase in the thickness of functionally graded material (FGM) core.

Free vibration of centrifugally stiffened axially functionally graded tapered Timoshenko beams using differential transformation and quadrature methods

The free bending vibration of rotating axially functionally graded (FG) Timoshenko tapered beams (TTB) with different boundary conditions are studied using Differential Transformation method (DTM) and differential quadrature element method of lowest order (DQEL). These two methods are capable of modelling any beam whose cross sectional area, moment of inertia and material properties vary along the beam. In order to verify the competency of these two methods, natural frequencies are obtained for problems by considering the effect of material non-homogeneity, taper ratio, shear deformation parameter, rotating speed parameter, hub radius and tip mass. The results are tabulated and compared with the previous published results wherever available.