scholarly journals Design of a Novel Integrated Ultrasonic Tool Holder for Friction Stir Welding

2022 ◽  
Author(s):  
Jianzhong Ju ◽  
Zhili Long ◽  
Shuyuan Ye ◽  
Yongzhi Liu ◽  
Heng Zhao
Keyword(s):  
Elastic Modulus ◽  
Friction Stir Welding ◽  
Dynamic Performance ◽  
Vibration Measurement ◽  
Confined Space ◽  
Tightening Force ◽  
Friction Stir ◽  
Tool Holder ◽  
Steel Material ◽  
Welding Defects

Abstract Ultrasonic vibration used in friction stir welding (FSW) has shown advantages in reducing welding defects and improving welding quality. How to design an ultrasonic tool holder is a challenge because the holder is rotating in a confined space. In this study, we design a 20 kHz integrated ultrasonic tool holder in FSW. This novel configuration can be applied in general machining equipment. The elastic modulus is measured by non-destructive acoustic testing to attain the precise frequency. Three FSW transducers with alloy steel are designed by the modal analysis and the transducer prototypes are fabricated. The effect of pre-tightening force on transducer frequency is investigated, where the prestress of the piezoelectric stack instead of the torque is tested to achieve an optimal working frequency. The vibration of the transducers is measured by a Doppler Vibrometer System. It proved that the resonant frequencies are well consistent between simulation model and the experiment by the elastic modulus testing and the pre-tightening optimization. Moreover, the experiment demonstrates that the vibration amplitude is significantly different, even in a slight difference of steel material properties are adopted. The dynamic performance of the designed transducers is acceptable by the vibration measurement.

scholarly journals Longitudinal Residual Stress Analysis in AA2024-T3 Friction Stir Welding

2013 ◽  
Vol 7 (1) ◽  
pp. 18-26 ◽  
Author(s):  
Pierpaolo Carlone ◽  
Gaetano S. Palazzo
Keyword(s):  
Friction Stir Welding ◽  
Residual Stresses ◽  
Process Parameters ◽  
Material Properties ◽  
Stress Measurement ◽  
Dynamic Performance ◽  
Contour Method ◽  
Influence Of Process Parameters ◽  
Friction Stir ◽  
Longitudinal Residual Stress

Friction Stir Welding (FSW) is an innovative solid-state joining process, which is gaining a great deal of attention in several applicative sectors. The opportune definition of process parameters, i.e. minimizing residual stresses, is crucial to improve joint reliability in terms of static and dynamic performance. Longitudinal residual stresses, induced by FSW in AA2024-T3 butt joints, have been inferred by means of a recently developed technique, namely the contour method. Two approaches to stress measurement have been adopted; the former is based on the assumption of uniform material properties, the latter takes into account microstructural effects and material properties variations in the welding zones. The influence of process parameters, namely rotating and welding speeds, on stress distribution is also discussed.

Metallurgical Studies on the Friction Stir Welding of Dissimilar A356 and A413 Alloys

2012 ◽  
Vol 488-489 ◽  
pp. 345-349
Author(s):  
G. Elatharasan ◽  
V.S. Senthil Kumar
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Aluminum Alloys ◽  
Structural Characteristics ◽  
Grain Structure ◽  
Cast Aluminum ◽  
Friction Stir ◽  
Dissimilar Aluminum Alloys ◽  
Cast Aluminum Alloys ◽  
Welding Defects

Friction stir welding is a technique useful for joining aluminum alloys that are difficult to weld. In recent years, however the focuses has been on welding dissimilar aluminum alloys, and analyze their mechanical properties and micro-structural characteristics. In the present study, the less investigated welding of cast aluminum alloys is considered. Cast aluminum alloys, A356 and A413, commonly used in automotive and aerospace industries, were friction-stir welded and their mechanical properties and micro-structural characteristics were analyzed. On testing their welded region, no welding defects were observed. The welded region exhibited a maximum tensile strength of 90 N/mm2 and Vickers micro-hardness of 56.8. The micro-structural observations at the nugget region revealed a refined grain structure.

Thermo-Mechanical Modelling of Jointing Process by Friction Stir Welding of Aluminium-Based Composite Materials

2012 ◽  
Vol 188 ◽  
pp. 144-149
Author(s):  
Marius Pop-Calimanu ◽  
Traian Fleșer
Keyword(s):  
Composite Materials ◽  
Friction Stir Welding ◽  
High Speed ◽  
Active Element ◽  
Three Dimensional ◽  
Maximum Temperature ◽  
Friction Stir ◽  
Thermal Fields ◽  
Welding Defects ◽  
Dimensional Distribution

Jointing with rotary active element gains field through technological facilities offered nowadays. Own research have developed a model for studying the thermal fields and the plastic deformations of jointing composite materials Al/20%SiC combined by friction stir welding (FSW). In this article we will present the three-dimensional distribution of investigated fields, correlated with input parameters in the process. The process is performed with solid state components. The numerical results indicate that the maximum temperature in the FSW process increases with increasing speed of rotational tools. For high speed welding joint, should be increased, at the same time, the rotational speed to avoid welding defects.

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.

Phased Array Ultrasonic Testing for Post-Weld and OnLine Detection of Friction Stir Welding Defects

2016 ◽  
Vol 28 (4) ◽  
pp. 187-210 ◽  
Author(s):  
D. J. Huggett ◽  
M. W. Dewan ◽  
M. A. Wahab ◽  
A. Okeil ◽  
T. W. Liao
Keyword(s):  
Friction Stir Welding ◽  
Ultrasonic Testing ◽  
Phased Array ◽  
Online Detection ◽  
Friction Stir ◽  
Welding Defects
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