热轧加工协同提升Ti_(45)Zr_(40)Al_(5)Nb_(5)V_(5)轻质高熵合金强韧性能

Synergistic Enhancement of Toughness Properties of Ti_(45)Zr_(40)Al_(5)Nb_(5)V_(5) Lightweight High-Entropy Alloy by Hot Rolling Process

文章制备了一种密度为5.6 g/cm^(3)的新型轻质Ti_(45)Zr_(40)Al_(5)Nb_(5)V_(5)高熵合金,并研究了热轧温度对该合金的微观结构和力学性能的影响。从提升合金强韧性出发,采用不同的热轧温度对Ti_(45)Zr_(40)Al_(5)Nb_(5)V_(5)合金进行了轧制处理。并测定了同等40%变形量下(厚度从22 mm变为13.2 mm),700℃~1000℃的热轧温度时该合金的相结构、微观组织和拉伸力学性能。结果表明,热轧后Ti_(45)Zr_(40)Al_(5)Nb_(5)V_(5)合金始终保持单相BCC结构,晶粒尺寸下降了25.6%~53.7%,而且拉伸强度随热轧温度先升高后下降,延伸率不断升高。最佳的热轧温度为800℃,此时合金具有202μm的平均晶粒尺寸、917 MPa的拉伸屈服强度和11.3%的延展性,晶粒细化和位错强化是其性能提升的根本原因,该研究有望为高强韧化轻质金属结构材料的研发提供理论依据。

In this paper,a new lightweight Ti_(45)Zr_(40)Al_(5)Nb_(5)V_(5) high-entropy alloy with a density of 5.6 g/cm^(3) was prepared,and the effects of hot rolling temperature on the microstructure and mechanical properties of the alloy were investigated.Starting from enhancing the strong toughness of the alloy,different hot rolling temperatures were used to roll the Ti_(45)Zr_(40)Al_(5)Nb_(5)V_(5) alloy.The phase structure,microstructure and tensile mechanical properties of the alloy were also determined for the same 40%deformation(thickness changed from 22 mm to 13.2 mm)at a hot rolling temperature of 700℃~1000℃.The results show that the Ti_(45)Zr_(40)Al_(5)Nb_(5)V_(5) alloy always maintains a single-phase BCC structure after hot rolling,and the grain size decreases by 25.6%~53.7%,and the tensile strength increases and then decreases with the hot rolling temperature,and the elongation increases continuously.The optimum hot rolling temperature is 800℃,at which time the alloy has an average grain size of 202μm,a tensile yield strength of 917 MPa and a ductility of 11.3%.Grain refinement and dislocation strengthening are the fundamental reasons for the improvement of its performance,which is expected to provide a theoretical basis for the research and development of high-strength and toughened lightweight metallic structural materials.