Analysis of the effect of structural defects on the fatigue strength of RFSSW joints using C‐scan scanning acoustic microscopy and SEM

• DOI: 10.1111/ffe.12984
• Publication Date: 2019-02-11T07:32:13Z
• Authors: Andrzej Kubit; Tomasz Trzepiecinski; Koen Faes; Mateusz Drabczyk; Wojciech Bochnowski; Marcin Korzeniowski
• Keywords: Friction Stir Welding; Spot welding; Fatigue limit

Abstract Solid‐state refill friction stir spot welding (RFSSW) technology offers significant benefits in the fabrication of aluminium structures transport and aerospace industries. In this paper, joining 1.6‐mm‐thick Alclad 7075‐T6 alloy sheets is investigated. High‐cycle fatigue strength tests single‐lap welded joints were carried out on an Instron E10000 testing machine with a limited number cycles equal to 2 × 10 6 . The overlap specimens was conducted using RPS100 welder by Harms & Wende GmbH Co KG. C‐mode scanning acoustic microscopy (C‐SAM) electron (SEM) utilised evaluate joint quality characterise microstructure. paper discusses effect maximum load force defects (voids, hook, kissing bond, bonding ligament, etc) associated material flow weld failure mechanism. Insufficient plasticisation sheet mixing area are crucial that influence destructive cycles. structure source decrease life compared defect‐free welds. It also found RFSSW can be effectively detected nondestructive C‐SAM method.