Annealing (glass)

Swaging

Biology

Electron backscatter diffraction

Metallurgy

Materials science

Ultimate tensile strength

Recrystallization (geology)

Ductility (Earth science)

Creep

Grain boundary

Paleontology

Alloy

Microstructure

Fracture toughness

Composite material

Toughness

Materials Science and Engineering A

Zirconium alloys are primarily used in nuclear applications as a cladding material due to its low neutron absorption, excellent mechanical strength, ductility, oxidation, and corrosion resistance properties. The effect of rotary-swaging feed rates (0.7 m/min, 1.25 m/min, and 2 m/min) and material-conditions (As-Received, Swaged, and Swaged+Annealed, 732 °C-3 h) on tensile, fracture toughness, and microstructural evolution of Zr-4 alloy were studied. Significant improvement has been observed in tensile strength (∼42%), ductility (∼37%), and fracture toughness (∼21%), especially in higher swaging (30%, ε=0.38, feed rate = 1.25 m/min) conditions. The ductility and fracture toughness (J-integral) were found maximum in swaged + annealed samples. The microstructural inhomogeneities are observed at centre and edge locations of swaged and annealed samples, investigated through EBSD. The in-depth microstructural mechanisms were explored through a transmission electron microscope (TEM) and X-ray diffraction analysis. The vital characteristic features such as dislocation-precipitate, dislocations-twin/grain boundary interactions, and ultrafine grain (UFG) evolution through dynamic recrystallization influences the strengthening mechanisms.

Effect of swaging feed rate and annealing phenomena on tensile, fracture toughness and microstructural evolution of Zr-4 alloy