变形诱导析出相实现Ti_(45)Zr_(40)A_(l5)Nb_(5)V_(5)轻质高熵合金强塑性协同提升

Improvement of Deformation Induced Precipitation Phase on Strength and Plasticity of Ti_(45)Zr_(40)A_(l5)Nb_(5)V_(5)Lightweight High Entropy Alloy

钛基高熵合金具有比强度高,低密度等优越性能,被军工业和科研界广泛关注。然而,如何寻找并通过改进加工手段获取兼顾强度和塑性的钛基高熵合金材料,建立起加工方式、材料微观组织和力学性能之间的联系仍需深入研究。文章通过真空悬浮熔炼制备了一种密度为5.6 g/cm3的新型高熵合金Ti45Zr40Al5Nb5V5,进一步采用多级轧制法强化并增韧合金。研究发现多级轧制诱导了Ti45Zr40Al5Nb5V5合金中B2和HCP析出相的形成。同时将晶粒尺寸由387μm减小到89.5μm。析出相和细晶强化相结合的方式协同提高了Ti45Zr40Al5Nb5V5材料的强度和塑性,材料的拉伸屈服强度提升了35.2%至1149 MPa,延展性提升到10%,相较于铸态合金提升了34.0%。

Titanium-based high-entropy alloys with superior properties such as high specific strength and low density have received much attention from the military industry and scientific research community.However,how to find and obtain titanium-based high-entropy alloy materials with both strength and plasticity through improved processing,and how to establish a relationship between processing methods,material microstructure and mechanical properties still need in-depth research.In this study,a new high-entropy alloy Ti_(45)Zr_(40)A_(l5)Nb_(5)V_(5)with a density of 5.6 g/cm3 was prepared by vacuum suspension melting,and the alloy was further strengthened and toughened by multi-stage rolling.It was found that multi-stage rolling induced the formation of B2 and HCP precipitated phases in Ti_(45)Zr_(40)A_(l5)Nb_(5)V_(5)alloy.The combination of precipitated phases and fine grain strengthening synergistically increased the strength and plasticity of Ti_(45)Zr_(40)A_(l5)Nb_(5)V_(5)material,and the tensile yield strength of the material was increased by 35.2%to 1,149 MPa,while the ductility of the material was increased by 34.0%to 10%.