Synergistic effects between potassium bubbles and high-energy-rate forging enabled ultrahigh strength and ductility of tungsten alloy

Abstract

The intrinsic brittleness of tungsten (W) significantly restricts its application as the primary material for plasma-facing components. In this study, we propose a novel approach to improve both the strength and ductility of W-based alloys based on the synergistic effects between potassium (K) bubbles and high-energy-rate forging. K doping was introduced into W, followed by a two-step high-energy-rate forging (HERF) process. This leads to laminated matrix grains with refined sizes and deformation textures, as well as an increase in the density of low-angle grain boundaries and smaller size K bubbles along the grain boundaries. As a result, the prepared W alloys exhibit a substantially reduced ductile-to-brittle transition temperature within the range of room temperature to 50 °C, along with a notable ultimate tensile strength of up to 1393 MPa. Impressively, these alloys also demonstrate remarkable elongation at 200 °C, reaching a value as high as 33.12%. The remarkable mechanical strength and exceptional ductility exhibited by these alloys highlight their considerable potential for commercial application in the field of nuclear fusion engineering.