Conventional material processing approaches often achieve strengthening of materials at the cost of reduced ductility. Here, we show that high-pressure and high-temperature (HPHT) treatment can help overcome the strength-ductility trade-off in structural materials. We report an initially strong-yet-brittle eutectic high entropy alloy simultaneously doubling its strength to 1150 MPa and its tensile ductility to 36% after the HPHT treatment. Such strength-ductility synergy is attributed to the HPHT-induced formation of a hierarchically patterned microstructure with coherent interfaces, which promotes multiple deformation mechanisms, including dislocations, stacking faults, microbands and deformation twins, at multiple length scales. More importantly, the HPHT-induced microstructure helps relieve stress concentration at the interfaces, thereby arresting interfacial cracking commonly observed in traditional eutectic high entropy alloys. These findings suggest a new direction of research in employing HPHT techniques to help develop next generation structural materials.

传统的材料加工方法通常以降低延展性为代价来实现材料的强化。在这里，我们证明高压高温（HPHT）处理可以帮助克服结构材料的强度-延展性权衡。我们报道了一种最初强而脆的共晶高熵合金，在 HPHT 处理后，其强度同时增加一倍，达到 1150 MPa，拉伸延展性提高到 36%。这种强度-延展性协同作用归因于高温高压诱导形成具有相干界面的分层图案化微观结构，从而促进多种变形机制，包括在多个长度尺度上的位错、堆垛层错、微带和变形孪晶。更重要的是，高温高压引起的微观结构有助于缓解界面处的应力集中，从而阻止传统共晶高熵合金中常见的界面裂纹。这些发现提出了利用高温高压技术帮助开发下一代结构材料的新研究方向。