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Miranda, Rosa M.; Gandra, João; Santos, Telmo G.; Quintino, Luísa; Santos Vilaca da Silva,PedroProcess Developments and Materials Characterization in FSW/P

Published in:3rd International Conference on scientific and technical advances on Friction Stir Welding & Processing,Central Nantes, France, 30-31 January 2014.

Published: 01/01/2014

Document VersionPublisher's PDF, also known as Version of record

Please cite the original version:Miranda, R. M., Gandra, J., Santos, T. G., Quintino, L., & Santos Vilaca da Silva, P. (2014). ProcessDevelopments and Materials Characterization in FSW/P. In 3rd International Conference on scientific andtechnical advances on Friction Stir Welding & Processing, Central Nantes, France, 30-31 January 2014.

Proceeding of the third international Conference Friction Stir Welding and Processing

FSWP'2014

CENTRALE NANTES, JANUARY 30 - 31 2014

Friction Stir Welding and Processing 2014

PROCESS DEYELOPMENTS AND MATERIALS CHARACTERIZATION IN FSW/P Rosa M. MIRANDA1, João GANDRA2, Telmo G. SANTOS1, Luisa QUINTIN02? Pedro VILACAa3

'UNIDEMI, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal, nniranda@fct.unl.pt, teimo.santos@fct.unl.pt 2Instituto Superior Técnico, Universidade Técnica de Lisboa, Av. Rovisco Pais 1, 1049-001 Lisboa, Portugal, ioao.gandra@ist.utl.pt, quintino@ist.utl.pt 'Department of Engineering Design and Production, School of Engineering. Aalto University, P.O. Box 1420, FI-00076 Aalto, Finland, pedro.vilaca@aalto.fi

Abstract FSW and processing have largely evolved in recent years in terms of process knowledge, materiais processed and industrial apllications. This paper aims at presenting some applications involving FSW and variants of this in distinct applications. Considering process developments friction stir has been studied in an hybrid welding process associated with electric current for welding Al based alloys. In this variant a temperatura increase due to Joule effect was seen to improve he viscoplasticity of base material without affecting metallurgical characteristics, reducing lack of penetration which is detrimental for fatigue resistance [1,2]. Diffusion welding triggered by FSW, named friction stir diffusin welding (FSDW) has also been investigated to join materiais with very distinctive properties as copper to stainless steel preventing the formation of brittle intermetallics and improving joining efficiency using downward force of 5500 N, rotation speed of 1800 rpm and travei speed of 90 mm/min. The same variant was tested to produce sandwich materiais as Al reinforced with NiTi ribbons taking advantage of the high conductive soft Al material and the damping capacity and high mecahnical resistance shown by NiTi. A good embedment of the reinforcing material under appropriate processing conditions was seen due to the viscoplastic material flow around the NiTi. The possibility to produce surface composites and functionally graded materiais by FSP and friction surfacing is another interesting field of research [3,4]. These find applications in components where high surface wear and corrosion resistances are a requirement. The introduction of SiC particles in Al based alloys allowed to produce orthogonal gradients of hardness and high surface resistances. Friction surfacing has also been studied aiming the two applications mentioned: to produce FGMs in non ferrous alloys and to manufacture high resistance coatings in steel. A very remarkable result is the high hardness observed in steel coatings much superior to those obtained with conventional heat treatments, as quenching. A hardness of 700 HV was measured in A1SIH13 coatings due to both the rapid quenching of high temperature material and severe plastic deformation of the process [5]. This solid state materiais processing technology also demands for new nondestructive techniques to assess the materiais integrity and characterize the processed area. Thus, eddy currents have been studied and showed to map the microstructures of distint zones. as well as, to identify LoP defects [6,7].

Keywords: FSW, FSP, diffusion joining assisted by FSW, friction surfacing, Eddy currents, composites Acknowledgement: Work reported was supported by the grant project FRISURF funded by Fundação para a Ciência e Tecnologia and Pest OE/EME/UI0667/2011.

References

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Friction Stir Welding and Processing 2014

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[5] J. Gandra, R. Miranda, P. Vilaça, A. Velhinho, J. Pamies Teixeira. Producing functionally graded materiais by friction stir processing. Journal of Materials Processing Technology, 211(11), 1659-1668,2011

[6] J. Gandra. New developments in Friction Surfacing for industrial applications. PhD thesis, IST, Portugal, 2013.

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[8] T. G. Santos, P. Vilaça, L. Quintino. Application of eddy current techniques to inspect friction spot welds in aluminium alloy AA2024 and a composite material. Welding in the World, 55(9-10), 12-18,2011.

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