Influence of Interlayer Thickness (Zn) on the Properties of Al 7020 FSW Joints

• Autor(a) principal: Lenin,Anselm Wilson Annammal
• Data de Publicação: 2016
• Outros Autores: Periyasamy,Nagaraj, George,Lincy
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Materials research (São Carlos. Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392016000400817
• topic: FSW; Al7020 Joining; Zn interlayer; Microstructure; mechanical Properties; Acoustic Emission

The use of lightweight materials in the production of cryogenic tanks, spacecraft body etc. are becoming the need to develop dissimilar metal FSW joints. Friction stir welding (FSW) is a novel and inspired light metal joining process since it is not involved with the melting of the parent metal. In this work, two Aluminium 7020 plates were welded with Zn as an interlayer, using friction stir welding method. Different joints were made by varying the thickness of interlayer (Zn) and thereafter the characterization is done against mechanical properties and microstructure of weld nugget. The test result shows that the specimen joint with 10μ Zn interlayer has higher mechanical properties than samples made with 5μ, 10μ, 20μ, 40μ and 100μ Zn interlayer. To analyze the cause, further optical studies (Image analyzer and SEM analysis) were carried out and found the interlayer dispersion plays a vital role in weld strength. As a conclusion addition of Zinc interlayer with preferable thickness (10μ) in Al7020 FSW joints improve tensile strength and hardness than the FSW joints made with higher and lower interlayer thickness.