热处理对(Co_(40)Cr_(25)Fe_(15.5)Ni_(15.5)Mo_(4))_(99.5)C_(0.5)高熵合金组织及性能的影响

Effect of Annealing on the Microstructure and Properties of(Co_(40)Cr_(25)Fe_(15.5)Ni_(15.5)Mo_(4))_(99.5)C_(0.5) High Entropy Alloy

高熵合金作为一种新型的材料研究方向,在本世纪得到了广泛的关注。用真空电弧熔炼制备(Co_(40)Cr_(25)Fe_(15.5)Ni_(15.5)Mo_(4))_(99.5)C_(0.5)高熵合金,经过均匀化和轧制工艺,研究了不同退火温度对高熵合金组织及性能的影响。结果表明:退火态合金由面心立方结构(FCC)相构成,合金组织形貌为等轴晶,析出相富集C、Mo元素,细晶强化作用提高了材料强度。随着退火温度的提高,高熵合金的屈服强度和抗拉强度以及硬度逐步下降,延伸率增大,合金塑性随温度上升而增大。退火孪晶减少,塑性提高,材料由脆性断裂向韧性断裂转变。

As a new material research direction,high entropy alloy has attracted widespread attention.In this work,(Co_(40)Cr_(25)Fe_(15.5)Ni_(15.5)Mo_(4))_(99.5)C_(0.5) high entropy alloy was fabricated through an arc-melting and casting process.As-cast alloy was homogenized and rolling to investigate the effect of different annealing temperatures on the microstructure and properties of high entropy alloy.Results show that the alloy annealed state by the FCC phase,the microstructure of the alloy is equiaxed crystal,C,Mo element is enriched in precipitated phase.Fine grain strengthening improves the strength of the material.With the increasing of annealing temperature,the HEA′s yield strength,tensile strength,hardness gradually decrease and elongation increase.The alloy plasticity increases with temperature rise.Annealing twins are reduced,plasticity is improved,and the material changes from brittle fracture to ductile fracture.