A Study of Friction Stir Welding of High Density Polyethylene

2018 ◽  
Author(s):  
Jamal Sheikh-Ahmad ◽  
Dima Ali ◽  
Firas Jarrar ◽  
Suleyman Deveci
Keyword(s):  
Friction Stir Welding ◽  
High Density Polyethylene ◽  
Elevated Temperatures ◽  
Welding Process ◽  
High Density ◽  
Weld Quality ◽  
Welding Zone ◽  
Friction Stir ◽  
Welding Processes ◽  
Material Temperature

Friction stir welding of high density polyethylene sheets was performed at different rotational and welding speeds and the material temperature close to the welding zone was monitored by infrared thermography and thermocouple measurements. Welding quality was evaluated by macrostructure analysis and tensile testing. Fracture surfaces of the tensile specimens were also analyzed. It was found that weld quality is highly dependent on the temperature of the material in the welding zone. For some specific welding conditions the welding process was unstable due to elevated temperatures reaching the melting point of HDPE. Instability of the welding processes was characterized by cyclic material temperatures and down forces. Decreasing the welding speed and increasing the rotational speed was found to improve weld quality.

Investigation of the effects of welding variables on the welding defects of the friction stir welded high density polyethylene sheets

2021 ◽  
pp. 009524432110588
Author(s):  
Mustafa Kemal Bilici
Keyword(s):  
Friction Stir Welding ◽  
High Density Polyethylene ◽  
Welding Process ◽  
High Strength ◽  
High Density ◽  
Welding Parameters ◽  
Friction Stir ◽  
Wide Range ◽  
Welding Defects ◽  
Welding Processes

Modern thermoplastic materials are used in an expanding range of engineering applications, such as in the automotive industry, due to their enhanced stress-to-weight ratios, toughness, a very short time of solidification, and a low thermal conductivity. Recently, friction stir welding has started to be used in joining processes in these areas. There are many factors that affect weld performance and weld quality in friction stir welding (FSW). These factors must be compatible with each other. Due to the large number of welding variables in friction stir welding processes, it is very difficult to achieve high strength FSW joints, high welding performance, and control the welding process. Welding variables that form the basis of friction stir welding; machine parameters, tool variables, and material properties are divided into three main groups. Each welding variable has different effects on the weld joint. In this study, friction stir welds were made on high density polyethylene (HDPE) sheets with factors selected from machine parameters and welding tool variables. Although the welding performance, quality, and strength gave good results in some conditions, successful joints could not be realized in some conditions. In particular, welding defects occurring in the combination of HDPE material with FSW were investigated. Welding quality, defects, and performances were examined with macrostructure. In addition, the tensile strength values of some the joints were determined. The main purpose of this study is to determine the welding defects that occur at the joints. The causes of welding defects, prevention methods, and which weld variables caused were investigated. Welding parameters and welding defects caused by welding tools were examined in detail. In addition, the factors causing welding defects were changed in a wide range and the changes in the defects were observed.

Modeling of the Plastic Characteristics of AA6082 for the Friction Stir Welding Process

2015 ◽  
Vol 639 ◽  
pp. 309-316
Author(s):  
Sergio Pellegrino ◽  
Livan Fratini ◽  
Marion Merklein ◽  
Wolfgang Böhm ◽  
Hung Nguyen
Keyword(s):  
Friction Stir Welding ◽  
Strain Rate ◽  
Elevated Temperatures ◽  
Flow Behavior ◽  
Welding Process ◽  
Rate Sensitivity ◽  
Tensile Tests ◽  
Friction Stir ◽  
Friction Stir Welding Process ◽  
Welding Processes

Focus of this paper is to model the plastic forming behavior of AA6082, in order to develop the numerical FE analysis of the friction stir welding processes and the simulation of subsequent forming processes. During the friction stir welding process, the temperatures reached are until 500 °C and have a fundamental role for the correct performance of the process so the material data has to show a temperature dependency. Because of the tool rotation a strain rate sensitivity of the material has to be respected as well. In this context, the general material characteristics of AA6082 were first identified for different stress states. For the uniaxial state the standard PuD-Al used in the automotive industry was applied, for the shear state the ASTM B831-05 was used and for biaxial states the ISO 16842 was exploited. To characterize the plastic flow behavior of the AA6082 at elevated temperatures tensile tests were performed according to DIN EN ISO 6892-2 from 25 °C until 500 °C with a strain rate from 0.1 s-1up to 6.5 s-1.

Experimental Study on the Effects of Rotational Speed and Attack Angle on High Density Polyethylene (HDPE) Friction Stir Welded Butt Joints

2011 ◽  
Vol 189-193 ◽  
pp. 3583-3587 ◽  
Author(s):  
Sina Saeedy ◽  
M.K. Besharati Givi
Keyword(s):  
Rotational Speed ◽  
High Density Polyethylene ◽  
Base Material ◽  
Welding Process ◽  
High Density ◽  
Attack Angle ◽  
Material Strength ◽  
Weld Quality ◽  
Welding Condition ◽  
Friction Stir

Friction stir welding (FSW) is a novel solid-state welding process and has been employed in several industries such as aerospace and automotive. Several parameters such as rotational speed, welding speed, axial force and attack angle play critical roles in FSW process in order to analyze the weld quality. The aim of this study is to investigate the effects of different rotational speeds and attack angles on the weld quality of high density polyethylene (HDPE). In the optimum welding condition, 75% of the base material strength is achieved. SEM micrographs show the changes of the weld microstructure which result in the reduction of the strength and the percent of elongation.

scholarly journals Parametric Study Of Friction Stir Spot Welding (FSSW) For Polymer Materials Case Of High Density Polyethylene Sheets: Experimental And Numerical Study

2020 ◽  
Vol 15 (55) ◽  
Author(s):  
Djilali Benyerou ◽  
El Bahri Ould Chikh ◽  
Habib Khellafi ◽  
Hadj Miloud Meddah ◽  
Ali Benhamena ◽  
...  
Keyword(s):  
Finite Element ◽  
Numerical Modeling ◽  
High Density Polyethylene ◽  
Spot Welding ◽  
Welding Process ◽  
Friction Stir Spot Welding ◽  
High Density ◽  
Polymer Materials ◽  
Friction Stir ◽  
Welding Processes

Friction stir spot welding (FSSW) is a very important part of conventional friction stir welding (FSW) which can be a replacement for riveted assemblies and resistance spot welding. This technique provides high quality joints compared to conventional welding processes. Friction stir spot welding (FSSW) is a new technology adopted to join various types of metals such as titanium, aluminum, magnesium. It is also used for welding polymer materials which are difficult to weld by the conventional welding process. In various industrial applications, high density polyethylene (HDPE) becomes the most used material. The parameters and mechanical properties of the welds are the major problems in the welding processes. In this paper, we have presented a contribution in finite element modeling of the friction stir spot welding process (FSSW) using Abaqus as a finite element solver. The objective of this paper is to study the HDPE plates resistance of stir spot welding joints (FSSW). First, we show the experimental tests results of high-density polyethylene (HDPE) plates assembled by friction stir spot welding (FSSW). Three-dimensional numerical modeling by the finite element method makes it possible to determine the best representation of the weld joint for a good prediction of its behavior. Comparison of the results shows that there is a good agreement between the numerical modeling predictions and the experimental results.

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

2018 ◽  
Vol 32 (9) ◽  
pp. 640-649
Author(s):  
Yorledis Macea Romero ◽  
Mirley Moreno Moreno ◽  
Beatriz Arrieta Cardozo ◽  
William Plata Rueda ◽  
Salomón Consuegra Pacheco ◽  
...  
Keyword(s):  
Friction Stir Welding ◽  
High Density Polyethylene ◽  
High Density ◽  
Friction Stir

Numerical Study of the Tool Rake Angle Effect on the Material Flow in Friction Stir Welding Process

2007 ◽  
Author(s):  
Hosein Atharifar ◽  
Radovan Kovacevic
Keyword(s):  
Friction Stir Welding ◽  
Material Flow ◽  
Numerical Study ◽  
Welding Process ◽  
Rake Angle ◽  
Heat Transfer Analysis ◽  
Tool Geometry ◽  
Friction Stir ◽  
Tool Pin ◽  
Welding Processes

Minimizing consumed energy in friction stir welding (FSW) is one of the prominent considerations in the process development. Modifications of the FSW tool geometry might be categorized as the initial attempt to achieve a minimum FSW effort. Advanced tool pin and shoulder features as well as a low-conductive backing plate, high-conductive FSW tools equipped with cooling fins, and single or multi-step welding processes are all carried out to achieve a flawless weld with reduced welding effort. The outcomes of these attempts are considerable, primarily when the tool pin traditional designs are replaced with threaded, Trifiute or Trivex geometries. Nevertheless, the problem remains as to how an inclined tool affects the material flow characteristics and the loads applied to the tool. It is experimentally proven that a positive rake angle facilitates the traverse motion of the FSW tool; however, few computational evidences were provided. In this study, numerical material flow and heat transfer analysis are carried out for the presumed tool rake angle ranging from −4° to 4°. Afterwards, the effects of the tool rake angle to the dynamic pressure distribution, strain-rates, and velocity profiles are numerically computed. Furthermore, coefficients of drag, lift, and side force and moment applied to the tool from the visco-plastic material region are computed for each of the tool rake angles. Eventually, this paper confirms that the rake angle dramatically affects the magnitude of the loads applied to the FSW tool, and the developed advanced numerical model might be used to find optimum tool rake angle for other aluminum alloys.

Solid State Welding Process for Aerospace Components

2015 ◽  
Vol 1119 ◽  
pp. 597-600
Author(s):  
Hyun Ho Jung ◽  
Ye Rim Lee ◽  
Jong Hoon Yoon ◽  
Joon Tae Yoo ◽  
Kyung Ju Min ◽  
...  
Keyword(s):  
Friction Stir Welding ◽  
Solid State ◽  
Structural Integrity ◽  
Welding Process ◽  
Diffusion Welding ◽  
Intimate Contact ◽  
Friction Stir ◽  
Base Materials ◽  
Welding Processes ◽  
And Diffusion

Since solid state welded joint is formed from an intimate contact between two metals at temperatures below the melting point of the base materials, the structural integrity of welding depends on time, temperature, and pressure. This paper provides some of examples of friction stir welding and diffusion welding process for aerospace components. Friction stir welding process of AA2195 was developed in order to study possible application for a large fuel tank. Massive diffusion welding of multiple titanium sheets was performed and successful results were obtained. Diffusion welding of dissimilar metals of copper and stainless steel was necessary to manufacture a scaled combustion chamber. Diffusion welding of copper and steel was performed and it is shown that the optimum condition of diffusion welding is 7MPa at 890°C, for one hour. It is shown that solid state welding processes can be successfully applied to fabricate lightweight aerospace parts.

Modeling Damage Evolution in Friction Stir Welding Process

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Youliang He ◽  
Paul R. Dawson ◽  
Donald E. Boyce
Keyword(s):  
Friction Stir Welding ◽  
Void Growth ◽  
Evolution Equations ◽  
Volume Fraction ◽  
Welding Process ◽  
Three Dimensions ◽  
Element Formulation ◽  
Operational Parameters ◽  
Friction Stir ◽  
Welding Processes

The evolution of voids (damage) in friction stir welding processes was simulated using a void growth model that incorporates viscoplastic flow and strain hardening of incompressible materials during plastic deformation. The void growth rate is expressed as a function of the void volume fraction, the effective deformation rate, and the ratio of the mean stress to the strength of the material. A steady-state Eulerian finite element formulation was employed to calculate the flow and thermal fields in three dimensions, and the evolution of the strength and damage was evaluated by integrating the evolution equations along the streamlines obtained in the Eulerian configuration. The distribution of internal voids within the material was qualitatively compared with experimental results, and a good agreement was observed in terms of the spatial location of voids. The effects of pin geometry and operational parameters such as tool rotational and travel speeds on the evolution of damage were also examined.

scholarly journals A Multi-attribute Control Chart for Monitoring Friction Stir Welding Process Considering Small Sample Sizes

2018 ◽  
Vol 23 (4) ◽  
pp. 474-484
Author(s):  
Esmeralda Ramírez-Méndez ◽  
Mario Cantu-Sifuentes ◽  
David Salvador González-González ◽  
Argelia Fabiola Miranda-Pérez ◽  
Rolando Javier Praga-Alejo
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Control Chart ◽  
Welding Process ◽  
Small Sample ◽  
Sample Sizes ◽  
Process Data ◽  
Friction Stir ◽  
Small Sample Sizes ◽  
Welding Processes

Abstract Often, welding processes used in the industry affect the mechanical properties of materials and quality of a manufactured product. There is, however, an alternative process named Friction Stir Welding (FSW), which is an solid state welding process developed to weld light alloys without compromising their mechanical properties. It is of interest to monitor the performance of FSW process to detect loss of quality. In practice, superficial and internal defects can be found; they can be identified through simple visual inspection and through visual recognition on destructive testing respectively, both procedures represent inspection by attributes. Therefore a multi-attribute control chart is assessed to monitor the process. Commonly, multi-attribute control charts involve high sampling rates to ensure accurate monitoring. In this paper, a multi-attribute control chart is proposed, considering the use of empirical control limits, instead of the theoretical ones, in order to improve its accuracy and lessen the small sample sizes effect. The performance of proposed approaches is analyzed by means of Monte Carlo simulation. The results suggest that the performance of the empirical designs is better than the theoretical ones in all tested cases. Finally, the results of monitoring FSW process data are detailed.

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