In the present work, Ti6Al4V alloy was treated by one/two passes explosion hardening (EH) technique to enhance mechanical properties. The phase structures, grain size distribution, dislocation and twin structures of EH treated Ti6Al4V alloy were characterized in detail. Mechanical properties of EH treated Ti6Al4V alloy were measured by tensile and compressive tests. The mechanism of shock-induced strengthening was subsequently analyzed. Experimental results showed that gradient grain microstructure with nanotwins/hierarchical nanotwins and β-α phase transformation occurred near the surface of EH treated Ti6Al4V alloy. Furthermore, the tensile and compressive strengths of Ti6Al4V alloy exhibited significant enhancement after EH treatment. The compressive strength of the materials increased from 1008 MPa in untreated condition to 1121 MPa in one pass EH treatment and 1365 MPa in two passes EH treatment, while the fracture strains always remained more than 0.15. The significant strengthening of Ti6Al4V alloy after two passes EH treatment was mainly attributed to the formation of hierarchical nanotwins, which can effectively impede dislocation motion. In summary, EH is an effective technique to improve mechanical properties of Ti6Al4V alloy by producing gradient microstructure with hierarchical nanotwins. The present research may have the potential use for metallic materials in the field of load-carrying capacity, tribological property and fatigue property.

在目前的工作中，Ti6Al4V 合金通过一次/两次爆炸硬化 (EH) 技术处理以提高机械性能。详细表征了EH处理的Ti6Al4V合金的相结构、晶粒尺寸分布、位错和孪晶结构。通过拉伸和压缩试验测量了 EH 处理的 Ti6Al4V 合金的力学性能。随后分析了冲击诱导强化的机制。实验结果表明，在EH处理的Ti6Al4V合金表面附近出现了具有纳米孪晶/分级纳米孪晶和β-α相变的梯度晶粒显微组织。此外，EH 处理后 Ti6Al4V 合金的抗拉强度和抗压强度显着提高。材料的抗压强度从未处理条件下的1008 MPa提高到一次EH处理的1121 MPa和两次EH处理的1365 MPa，而断裂应变始终保持在0.15以上。Ti6Al4V 合金在两次 EH 处理后的显着强化主要归因于分级纳米孪晶的形成，可以有效地阻止位错运动。总之，EH 是一种通过产生具有分级纳米孪晶的梯度微观结构来提高 Ti6Al4V 合金力学性能的有效技术。本研究可能对金属材料在承载能力、摩擦学性能和疲劳性能领域具有潜在的应用价值。Ti6Al4V 合金在两次 EH 处理后的显着强化主要归因于分级纳米孪晶的形成，可以有效地阻止位错运动。总之，EH 是一种通过产生具有分级纳米孪晶的梯度微观结构来提高 Ti6Al4V 合金力学性能的有效技术。本研究可能对金属材料在承载能力、摩擦学性能和疲劳性能领域具有潜在的应用价值。Ti6Al4V 合金在两次 EH 处理后的显着强化主要归因于分级纳米孪晶的形成，可以有效地阻止位错运动。总之，EH 是一种通过产生具有分级纳米孪晶的梯度微观结构来提高 Ti6Al4V 合金力学性能的有效技术。本研究可能对金属材料在承载能力、摩擦学性能和疲劳性能领域具有潜在的应用价值。