Strain and strain rate during friction stir welding/processing of Al-7Si-0.3Mg alloy

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.

Download Full-text

Temperature fields in linear stage of friction stir welding: Effect of different material properties

Thermal Science ◽

10.2298/tsci181015264v ◽

2019 ◽

Vol 23 (6 Part B) ◽

pp. 3985-3992

Author(s):

Darko Veljic ◽

Marko Rakin ◽

Bojan Medjo ◽

Mihailo Mrdak ◽

Aleksandar Sedmak

Keyword(s):

Friction Stir Welding ◽

Numerical Models ◽

Welding Process ◽

High Strength ◽

Temperature Fields ◽

Arbitrary Lagrangian Eulerian ◽

Friction Stir ◽

Strain And Strain Rate ◽

The Difference ◽

Weld Area

Friction stir welding is one of the procedures for joining the parts in solid state. Thermo-mechanical simulation of the friction stir welding of high-strength aluminium alloys 2024 T3 and 2024 T351 is considered in this work. Numerical models corresponding to the linear welding stage are developed in Abaqus software package. The material behaviour is modelled by Johnson-Cook law (which relates the yield stress with temperature, strain and strain rate), and the Arbitrary Lagrangian-Eulerian technique is applied. The difference in thermo-mechanical behaviour between the two materials has been analysed and commented. The main quantities which are considered are the temperature in the weld area, plastic strain, as well as the rate of heat generation during the welding process.

Download Full-text

Fully coupled thermomechanical finite element analysis of material evolution during friction-stir welding of AA5083

Proceedings of the Institution of Mechanical Engineers Part B Journal of Engineering Manufacture ◽

10.1243/09544054jem1750 ◽

2009 ◽

Vol 224 (4) ◽

pp. 609-625 ◽

Cited By ~ 50

Author(s):

M Grujicic ◽

T He ◽

G Arakere ◽

H V Yalavarthy ◽

C-F Yen ◽

...

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Friction Stir Welding ◽

Computational Approach ◽

Material Strength ◽

Element Analysis ◽

Friction Stir ◽

Ale Formulation ◽

Strain And Strain Rate ◽

Fully Coupled

Interactions between the rotating and advancing pin-shaped tool (terminated at one end with a circular—cylindrical shoulder) with the clamped welding plates and the associated material and heat transport during a friction-stir welding (FSW) process are studied computationally using a fully coupled thermomechanical finite element analysis. To surmount potential numerical problems associated with extensive mesh distortions/entanglement, an arbitrary Lagrangian—Eulerian (ALE) formulation was used, which enabled adaptive remeshing (to ensure the continuing presence of a high-quality mesh) while allowing full tracking of the material-free surfaces. To demonstrate the utility of the present computational approach, the analysis is applied to the case of FSW of AA5083 (a solid—solution strengthened and strain-hardened/stabilized Al—Mg wrought alloy). To account for the competition between plastic deformation-controlled strengthening and dynamic recrystallization-induced softening phenomena during the FSW process, the original Johnson—Cook strain and strain-rate hardening and temperature-softening material strength model is modified using the available recrystallization kinetics experimental data. Lastly, the computational results obtained in the present work are compared with their experimental counterparts available in the open literature. This comparison revealed that general trends regarding spatial distribution and temporal evolutions of various material-state quantities and their dependence on the FSW process parameters are reasonably well predicted by the present computational approach.

Download Full-text

Strain rate dependent micro-texture evolution in friction stir welding of copper

Materialia ◽

10.1016/j.mtla.2019.100302 ◽

2019 ◽

Vol 6 ◽

pp. 100302 ◽

Cited By ~ 7

Author(s):

X.C. Liu ◽

Y.F. Sun ◽

T. Nagira ◽

K. Ushioda ◽

H. Fujii

Keyword(s):

Friction Stir Welding ◽

Strain Rate ◽

Texture Evolution ◽

Friction Stir ◽

Rate Dependent

Download Full-text

EFFECT OF PROCESS PARAMETERS ON TEMPERATURE DISTRIBUTION, STRAIN RATE AND FLOW-STRESS DURING FRICTION STIR WELDING OF ALUMINIUM ALLOY

International Journal of Research in Engineering and Technology ◽

10.15623/ijret.2016.0518007 ◽

2016 ◽

Vol 05 (18) ◽

pp. 26-32

Author(s):

Mohd Anees Siddiqui .

Keyword(s):

Friction Stir Welding ◽

Flow Stress ◽

Temperature Distribution ◽

Strain Rate ◽

Aluminium Alloy ◽

Process Parameters ◽

Friction Stir

Download Full-text

On the friction stir welding, tool design optimization, and strain rate-dependent mechanical properties of HDPE–ceramic composite joints

Journal of Thermoplastic Composite Materials ◽

10.1177/0892705717697779 ◽

2017 ◽

Vol 31 (3) ◽

pp. 291-310 ◽

Cited By ~ 2

Author(s):

Kabeer Raza ◽

Muhammad Shamir ◽

Muhammad Kashan Akhtar Qureshi ◽

Abdul Shaafi Shaikh ◽

Muhammad Zain-ul-abdein

Keyword(s):

Friction Stir Welding ◽

Strain Rate ◽

Tensile Properties ◽

Welded Joints ◽

Tool Design ◽

Welding Parameters ◽

Composite Joints ◽

Friction Stir ◽

Composite Joint ◽

Joint Efficiency

Friction stir welding is a recently developed technique for joining low-melting metals and polymers. In the present work, friction stir welded joints of high-density polyethylene (HDPE) sheets were produced using a newly designed tool with a concave shoulder and a grooved conical pin. The joints were produced with and without the additions of ceramic particulates including silicon carbide (SiC), alumina, graphite, and silica. The effect of strain rate on the tensile properties of base material and plain welded joints was examined. In addition to tensile properties of composite joints, hardness profiles across the weld nugget were analyzed. It was observed that the increasing strain rate improved both the tensile strength and the ductility of the plain welded joints. The tool was able to yield a joint efficiency of around 84% in the plain welded samples. Although, in terms of joint efficiency, the composite joints were less efficient than the plain welded HDPE, SiC additions were found to yield better material properties relative to other reinforcements. Finally, it was concluded that an SiC–HDPE composite joint can be of practical importance in high strain rate applications, provided the optimum tool design and stir welding parameters are available.

Download Full-text