Si和C的添加对Fe_(2.5)CoNiCu高熵合金显微组织和力学性能的影响

Influences of Si and C addition on microstructure and mechanical properties of Fe_(2.5)CoNiCu high-entropy alloy

为了评估非金属元素(Si和C)对Fe_(2.5)CoNiCu高熵合金显微组织演变和力学性能的影响,采用真空感应熔炼法制备Fe_(2.5)CoNiCuSix(x=0.1~0.3,摩尔分数)和Fe_(2.5)CoNiCuCx(x=0.15~0.4,摩尔分数)两种系列高熵合金。结果表明,C和Si的加入显著促进BCC/FCC双相向单一FCC结构的转变,且添加C对BCC/FCC组织演变的影响更明显。Fe_(2.5)CoNiCuSi0.2高熵合金具有较高的硬度(HV439.5)和抗拉强度(868MPa),这与固溶强化和晶粒细化作用有关。随着C含量的增加,Fe_(2.5)CoNiCuCx高熵合金的硬度和强度均增加,这是碳化物的形成和固溶强化所致。这表明在高熵合金中添加非金属元素(C或Si)是提高合金强度和硬度的可行途径。

To evaluate the role of non-metallic element(Si and C)on the microstructural evolution and mechanical properties of Fe_(2.5)CoNiCu high-entropy alloys(HEAs),two series of Fe_(2.5)CoNiCuSix(x=0.1-0.3,molar fraction)and Fe_(2.5)CoNiCuCx(x=0.15-0.4,molar fraction)HEAs were prepared by vacuum induction melting.The results show that the amounts of C and Si additions significantly stimulate the transformation of BCC/FCC dual phases into a single FCC structure,and the microstructural evolution appears to be more strongly influenced by the C addition.The Fe_(2.5)CoNiCuSi0.2 HEA presents high hardness(HV 439.5)and tensile strength(868 MPa),which is attributed to the solution strengthening and grain refinement effect.Both the hardness and strength of Fe_(2.5)CoNiCuCx HEAs increase with the addition of C,due to the formation of carbides and solution strengthening.This demonstrates that adding non-metallic element(C or Si)is a viable approach for enhancing the strength and hardness of HEAs.