Fe_(7)(CoNiMn)_(80)B_(13)共晶高熵合金的深过冷非平衡凝固行为及微观组织演变  

Non-Equilibrium Solidification Behavior and Microstructure Evolution of Undercooled Fe7(CoNiMn)80B13 Eutectic High-Entropy Alloy

作　　者：王叶青 付珂 赵永柱 苏礼季 陈正[1] WANG Yeqing;FU Ke;ZHAO Yongzhu;SU Liji;CHEN Zheng(School of Material Science and Physics,China University of Mining and Technology,Xuzhou 221116,China)

机构地区：[1]中国矿业大学材料与物理学院,徐州221116

出　　处：《金属学报》2025年第1期143-153,共11页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目Nos.52201055和52274401。

摘　　要：Fe_(7)(CoNiMn)_(80)B_(13)共晶高熵合金在非平衡凝固过程中存在复杂的相变及微观组织演变行为。为了揭示其非平衡凝固特征及组织演变机理,本工作采用熔融玻璃包覆法对Fe_(7)(CoNiMn)_(80)B_(13)共晶高熵合金进行了深过冷凝固,研究了该共晶高熵合金的深过冷凝固行为及微观组织演变特征。结果表明,Fe_(7)(CoNiMn)_(80)B_(13)共晶高熵合金在深过冷凝固过程中的凝固路径及凝固组织可以分为5类。在小过冷度下(ΔT<57 K),冷却曲线只有一次再辉现象,对应的凝固组织为初生富B相+α-(Fe,Co,Ni,Mn)包晶相+共晶组织。在中等过冷度下(ΔT=57~111 K),冷却曲线上出现2次再辉现象,对应的凝固组织可以分为2种:第一种为初生M_(23)B_(6)枝晶+次生α-(Fe,Co,Ni,Mn)晕圈+规则共晶;第二种为初生α-(Fe,Co,Ni,Mn)枝晶+规则共晶。在大过冷度下(ΔT=139~198 K),冷却曲线再次表现出单再辉现象,对应的凝固组织也可以分为2种:第一种为富B相+M_(23)B_(6)+α-(Fe,Co,Ni,Mn),3相各自存在;第二种为M_(23)B_(6)+α-(Fe,Co,Ni,Mn)的反常共晶。随着过冷度的增加,初生相的种类发生了2次转变:富B相→M_(23)B_(6)相→α-(Fe,Co,Ni,Mn)相。另外,小过冷度下获得的规则共晶中共晶2相的取向关系与大过冷度下获得的反常共晶中共晶2相的取向关系一致。Eutectic high-entropy alloys show excellent properties,such as casting property,mechanical properties,corrosion resistance properties,and so on.They are usually consisted of two kinds of phases,which would be compete with each other in the non-equilibrium solidification process.Fe_(7)(CoNiMn)_(80)B_(13) eutectic high-entropy alloy has complex phase transition and microstructure evolution behavior during the non-equilibrium solidification process.In order to reveal the non-equilibrium solidification characteristics and microstructure evolution mechanism,Fe_(7)(CoNiMn)_(80)B_(13) eutectic high-entropy alloy was undercooled by the molten glass fluxing method in this work.The results show that the solidification path and microstructure of undercooled Fe_(7)(CoNiMn)_(80)B_(13) eutectic high-entropy alloy can be divided into 5 categories.At low undercooling(ΔT<57 K),the cooling curve has only one recalescence phenomenon.The corresponding solidification microstructure is primary B-rich phase+peritectic α-(Fe,Co,Ni,Mn)phase+eutectic structure.At medium undercooling(ΔT=57~111 K),there are two recalescence phenomena on the cooling curve.The corresponding solidification microstructure can be divided into two types:the first is primary M_(23)B_(6) dendrite+secondary α-(Fe,Co,Ni,Mn)halo+regular eutectic;the second is primaryα-(Fe,Co,Ni,Mn)dendrite+regular eutectic.At high undercooling(ΔT=139~198 K),the cooling curve shows a single recalescence phenomenon again.The corresponding solidification microstructure can be divided into two types:the first is a mixture of B-rich phase+M_(23)B_(6)+α-(Fe,Co,Ni,Mn)three phases,and the second is M_(23)B_(6)+α-(Fe,Co,Ni,Mn)anomalous eutectic.Note that the type of primary phase transited for twice with the increase of undercooling:B-rich phase→M_(23)B_(6) phase→α-(Fe,Co,Ni,Mn)phase.In addition,the orientation relationship of two eutectic phases in regular eutectic at low undercooling is consistent with that of two phases in anomalous eutectic at high undercooling.

关 键 词：共晶高熵合金 深过冷凝固 非平衡凝固行为 微观组织 凝固路径 

分 类 号：TG21[金属学及工艺—铸造]