Additive manufacturing produces net-shaped components layer by layer for engineering applications^{1,2,3,4,5,6,7}. The additive manufacture of metal alloys by laser powder bed fusion (L-PBF) involves large temperature gradients and rapid cooling^2,6, which enables microstructural refinement at the nanoscale to achieve high strength. However, high-strength nanostructured alloys produced by laser additive manufacturing often have limited ductility³. Here we use L-PBF to print dual-phase nanolamellar high-entropy alloys (HEAs) of AlCoCrFeNi_2.1 that exhibit a combination of a high yield strength of about 1.3 gigapascals and a large uniform elongation of about 14 per cent, which surpasses those of other state-of-the-art additively manufactured metal alloys. The high yield strength stems from the strong strengthening effects of the dual-phase structures that consist of alternating face-centred cubic and body-centred cubic nanolamellae; the body-centred cubic nanolamellae exhibit higher strengths and higher hardening rates than the face-centred cubic nanolamellae. The large tensile ductility arises owing to the high work-hardening capability of the as-printed hierarchical microstructures in the form of dual-phase nanolamellae embedded in microscale eutectic colonies, which have nearly random orientations to promote isotropic mechanical properties. The mechanistic insights into the deformation behaviour of additively manufactured HEAs have broad implications for the development of hierarchical, dual- and multi-phase, nanostructured alloys with exceptional mechanical properties.

增材制造逐层生产用于工程应用的网状组件^{1,2,3,4,5,6,7}。通过激光粉末床熔合 (L-PBF) 增材制造金属合金涉及大温度梯度和快速冷却^2,6，这可以在纳米尺度上进行微结构细化以实现高强度。然而，通过激光增材制造生产的高强度纳米结构合金通常具有有限的延展性³。在这里，我们使用 L-PBF 打印 AlCoCrFeNi _{2.1的双相纳米层高熵合金 (HEA)}表现出约 1.3 吉帕斯卡的高屈服强度和约 14% 的大均匀伸长率的组合，超过了其他最先进的增材制造金属合金。高屈服强度源于由交替的面心立方和体心立方纳米片层组成的双相结构的强强化作用；体心立方纳米薄片比面心立方纳米薄片表现出更高的强度和更高的硬化率。大的拉伸延展性是由于嵌入在微尺度共晶菌落中的双相纳米薄片形式的印刷分层微观结构的高加工硬化能力而产生的，其具有几乎随机的取向以促进各向同性的机械性能。