TY - JOUR

T1 - Experimental and numerical analysis of refill friction stir spot welding of thin AA7075-T6 sheets

AU - Janga, Venkata Somi Reddy

AU - Awang, Mokhtar

AU - Yamin, Mohd Fadillah

AU - Suhuddin, Uceu F.H.

AU - Klusemann, Benjamin

AU - dos Santos, Jorge F.

N1 - The APC charges were covered under Yayasan UTP, grant No 015LCO-129. Acknowledgments: The authors offer their profound thanks to Universiti Teknologi PETRONAS for financial aid. This investigation has been conducted under the scope of DAHLIAS (Development and Application of Hybrid Joining in Lightweight Integral Aircraft Structures) project, funded by the European Union’ s HORIZON 2020 framework programme, Clean Sky 2 Joint Undertaking, and AIRFRAME ITD under grant agreement No 821081.

PY - 2021/12/6

Y1 - 2021/12/6

N2 - The refill friction stir spot welding (refill FSSW) process is a solid-state joining process to produce welds without a keyhole in spot joint configuration. This study presents a thermo-mechanical model of refill FSSW, validated on experimental thermal cycles for thin aluminium sheets of AA7075-T6. The temperatures in the weld centre and outside the welding zone at selected points were recorded using K-type thermocouples for more accurate validation of the thermo-mechanical model. A thermo-mechanical three-dimensional refill FSSW model was built using DEFORM-3D. The temperature results from the refill FSSW numerical model are in good agreement with the experimental results. Three-dimensional material flow during plunging and refilling stages is analysed in detail and compared to experimental microstructure and hardness results. The simulation results obtained from the refill FSSW model correspond well with the experimental results. The developed 3D numerical model is able to predict the thermal cycles, material flow, strain, and strain rates which are key factors for the identification and characterization of zones as well for determining joint quality.

AB - The refill friction stir spot welding (refill FSSW) process is a solid-state joining process to produce welds without a keyhole in spot joint configuration. This study presents a thermo-mechanical model of refill FSSW, validated on experimental thermal cycles for thin aluminium sheets of AA7075-T6. The temperatures in the weld centre and outside the welding zone at selected points were recorded using K-type thermocouples for more accurate validation of the thermo-mechanical model. A thermo-mechanical three-dimensional refill FSSW model was built using DEFORM-3D. The temperature results from the refill FSSW numerical model are in good agreement with the experimental results. Three-dimensional material flow during plunging and refilling stages is analysed in detail and compared to experimental microstructure and hardness results. The simulation results obtained from the refill FSSW model correspond well with the experimental results. The developed 3D numerical model is able to predict the thermal cycles, material flow, strain, and strain rates which are key factors for the identification and characterization of zones as well for determining joint quality.

KW - DEFORM-3D

KW - Finite element modelling

KW - Friction stir spot welding

KW - Hardness measurement

KW - Microstructure analysis

KW - Refill friction stir spot welding

KW - Simulation of joining process

KW - Temperature measurements

KW - Engineering

UR - http://www.scopus.com/inward/record.url?scp=85120771973&partnerID=8YFLogxK

U2 - 10.3390/ma14237485

DO - 10.3390/ma14237485

M3 - Journal articles

C2 - 34885638

AN - SCOPUS:85120771973

VL - 14

JO - Materials

JF - Materials

SN - 1996-1944

IS - 23

M1 - 7485

ER -