Confined fracture behavior of bulk metallic glass-coated tungsten composite wires produced by continuously coating process

The effects of thermal residual stresses on the tensile fracture behavior of the bulk metallic glass (BMG)-coated composite wires have been investigated by fabricating a series of BMG composite wires at varies drawing velocity. It is found that the coating thickness increases with the increase of drawing velocity and the axial and radial thermal stresses of the composite wires increase with the increase of the coating thickness. The values of axial thermal stresses are comparable with the tensile strength difference between the composite wires and the tungsten wire. Due to the effects of radial thermal stresses, the fracture mode change from the unconfined cleavage fracture of pure tungsten wire to confined step-like fracture mode of composite wires.

► BMG-coated composite wires with different coating thickness were synthesized.
► The axial and radical stresses at the interface were calculated by elasticity theory.
► The compressive axial thermal stresses slightly improved the tensile strength.
► The compressive radial thermal stresses lead the fracture mode to change.