Hydrogen embrittlement of additively manufactured AlCoCrFeNi_2.1 eutectic high-entropy alloy

AlCoCrFeNi_2.1 eutectic high-entropy alloy (HEA) was fabricated in as-cast and additively manufactured (AM) states. The hydrogen embrittlement susceptibility of both materials was investigated through in-situ uniaxial tensile test. Combining several advanced high-resolution scanning electron microscopy (SEM)-based techniques, the deformation and hydrogen embrittlement behavior have been intensively discussed. Interfacial cracking along both phase boundaries and grain boundaries are found to be responsible for the hydrogen-assisted fracture of this material. The cracking susceptibility has a dependence on the manufactured phase morphology. The orientation relationship between the phases and the misorientation between grains also have a significant impact on the hydrogen-induced cracks.