Achieving favorable strength and hydrogen embrittlement (HE) resistance synergy has long been one of the main challenges for developing structural materials. The current work reports a AlCoCrFeNi 2.1 eutectic high-entropy alloy with ultrahigh-strength and well HE resistance, achieved by well controlled selective laser melting process. The dislocation pile-up along the nano cellular B2 phase resulted in the high yield strength of 1065 MPa, ultimate tensile strength of 1263 MPa, and fracture strain of 25.3 %. Although the piled-up dislocations can also assist hydrogen concentration in B2/matrix ...
