A strong and ductile medium-entropy alloy resists hydrogen embrittlement and corrosion
Hong Luo, Seok Su Sohn, Wenjun Lu, Linlin Li, Xiaogang Li, Chandrahaasan K. Soundararajan, Waldemar Krieger, Zhiming Li, Dierk Raabe
Abstract
Abstract Strong and ductile materials that have high resistance to corrosion and hydrogen embrittlement are rare and yet essential for realizing safety-critical energy infrastructures, hydrogen-based industries, and transportation solutions. Here we report how we reconcile these constraints in the form of a strong and ductile CoNiV medium-entropy alloy with face-centered cubic structure. It shows high resistance to hydrogen embrittlement at ambient temperature at a strain rate of 10 −4 s −1 , due to its low hydrogen diffusivity and the deformation twinning that impedes crack propagation. Moreover, a dense oxide film formed on the alloy’s surface reduces the hydrogen uptake rate, and provides high corrosion resistance in dilute sulfuric acid with a corrosion current density below 7 μA cm −2 . The combination of load carrying capacity and resistance to harsh environmental conditions may qualify this multi-component alloy as a potential candidate material for sustainable and safe infrastructures and devices.