Plastic deformation of recrystallized tungsten-potassium wires: Constitutive deformation law in the temperature range 22–600 °C: WBS:

Recent efforts dedicated to the mitigation of tungsten (W) brittleness have demonstrated that tungsten fiberreinforced composites acquire extrinsic toughening even at room temperature, which is due to the outstanding strength of W wires. However, high temperature operation/fabrication of the fiber-reinforced composite might result in the degradation of the mechanical properties of Wwires. To address this, we investigate mechanical and microstructural properties of potassium-doped tungsten wires, being heat treated at 2300 °C and tested in temperature range 22–600 °C. Based on the microscopic analysis, the engineering deformation curves are converted into actual stress - strain dataset, accounting for the local necking. The analysis demonstrates that local strain in the necking region can reach up to 50% and the total elongation monotonically increases with temperature, while the ultimate tensile strength goes down. Preliminary transmission electron microscopy analysis using FIB-cut lamella from the necking region revealed the presence of curved dislocation lines in the sample tested at 300 °C, proving that plastic deformation occurred by dislocation glide.