Microstructure, tensile properties and fracture toughness of friction stir welded AA7075-T651 aluminium alloy joints
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Prabhuraj Parasuraman
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Tushar Sonar
Abstract
The main objective of this investigation is to study the microstructure, tensile properties and fracture toughness of friction stir welded (FSW) butt joints of 10 mm thick AA7075-T651 plates. The microstructural features of stir zone (SZ), thermos-mechanically affected zone (TMAZ), heat affected zone (HAZ) were analyzed using optical microscopy technique. The tensile properties were evaluated using smooth and notch tensile specimens and compared to base metal properties. The microhardness survey was done across the weld cross section and correlated to the failure of tensile specimens. Compact tension (CT) specimens were used to evaluate the fracture toughness of welded joints. The fractured tensile and CT specimens were analyzed using scanning electron microscopy (SEM). Results showed that the FSW AA7075-T651 specimens welded using axial load of 12 kN, tool rotation speed of 750 rpm and welding speed of 30 mm/min exhibited 412 MPa tensile strength and 9% elongation. It showed 88 and 89% of base metal strength elongation. The joints showed fracture toughness of 23 MPa m1/2 which is 80% of base metal fracture toughness. The superior tensile and fracture toughness properties of joints are mainly attributed to the evolution of finer grains in SZ due to the stirring action of FSW tool.
Acknowledgment
The authors express sincere gratitude to Director, Centre for Materials Joining and Research, CEMAJOR, Annamalai University, Annamalai Nagar, Tamil Nadu State, India for providing the welding and testing facility.
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Author contributions: All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission.
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Research funding: None declared.
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Conflict of interest statement: The authors declare no conflicts of interest regarding this article.
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Articles in the same Issue
- Frontmatter
- Effects of Re and Co additions on lattice parameters and lattice misfit in cast Ni-based superalloys
- Influence of pre- and post-weld heat treats on microstructures of laser welded GTD-111 with IN-718 as filler metal
- Examination of α′′, α′ and ω phases in a β-type titanium–niobium metal
- Corrosion resistance, thermal diffusivity and mechanical properties of Ni–SiO2 nanocomposite coatings on a 316 stainless steel for heat exchanger applications
- Influence of acidic media and chlorides on protective properties of epoxy coatings
- Effects of silver interlayer thickness on the microstructure and properties of electron beam welded joints of TC4 titanium and 4J29 Kovar alloys
- Influence of the mild steel coating application process, drying method and pigment on the surface topography
- Friction stir welding for manufacturing of a light weight combat aircraft structure
- Manufacturing and FSW of hybrid functionally graded metal matrix composite
- Effect of cryogenic treatment holding time on mechanical and microstructural properties of Sverker 21 steel
- Mechanical properties and microstructure evolution of Cf/SiC–Nb joints using Ti-base laminated foil
- Effect of nano graphene and CNT addition on coating properties in friction surfacing process
- Effect of ultra-high boron additions on microstructure and mechanical properties on high chromium steel
- Microstructure, tensile properties and fracture toughness of friction stir welded AA7075-T651 aluminium alloy joints
- NiTi-SiC composite coating on Ti6Al4V alloy produced by SHS using induction heating
- Corrosion resistance of commercial glazes of floor tiles
