强磁场下过冷Cu-Co/Cu-Co-Fe合金的凝固组织和摩擦性能  

Solidification Microstructure and Wear Properties of Undercooled Cu-Co/Cu-Co-Fe Alloys Under a High Magnetic Field

作　　者：魏晨 王军[1] 闫育洁 范嘉懿 李金山[1] WEI Chen;WANG Jun;YAN Yujie;FAN Jiayi;LI Jinshan(State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi'an 710072,China)

机构地区：[1]西北工业大学凝固技术国家重点实验室,西安710072

出　　处：《金属学报》2024年第11期1571-1583,共13页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目Nos.52174375和51690163;大学生创新创业计划资助项目No.S202210699088;陕西省创新能力支撑计划项目No.2020KJXX-073;凝固技术国家重点实验室自主课题项目No.2023-TS-13。

摘　　要：少数相均匀分布的难混溶合金是应用于制造电接触器件材料以及耐磨汽车部件的潜在替代品,理解难混溶合金微观组织的演化及其与磨损行为的相互关系对其工业应用十分重要。由于二元Cu-Co和三元Cu-Co-Fe难混溶合金易于发生液相分离,采用传统的铸造方法难以获得均匀的微观组织。本工作在强磁场下调控难混溶合金的微观组织,进而研究合金组织演化行为对摩擦性能的影响。实验结果表明,无磁场小过冷度下,Cu_(50)Co_(50)和Cu_(52)Co_(24)Fe_(24)难混溶合金的微观组织为枝晶形貌,大过冷度下Cu_(50)Co_(50)合金的微观组织为标准的核-壳结构,Cu_(52)Fe_(24)Co_(24)合金则为偏心的核-壳结构。随着磁场的施加,Cu_(50)Co_(50)和Cu_(52)Co_(24)Fe_(24)合金中的第二相均沿磁场方向被拉长,垂直磁场方向上合金中第二相尺寸均显著减小,但Cu_(52)Co_(24)Fe_(24)合金的微观组织分布更为均匀。无论是否施加强磁场,Cu_(50)Co_(50)和Cu_(52)Co_(24)Fe_(24)合金中具有大过冷度的试样均具有较好的耐磨性能。Cu_(50)Co_(50)和Cu_(52)Co_(24)Fe_(24)难混溶合金在磨损实验中均存在磨粒磨损和粘着磨损机制,其特征是材料脱落产生的粗糙表面以及滑动方向上存在的平行划痕。此外,Cu_(52)Fe_(24)Co_(24)合金较高的硬度以及磁场下微观组织的相对均匀分布,使其具有较好的耐磨性能。As functional metal materials,immiscible alloys demonstrate wide application prospects in industrial and electronic fields.Immiscible alloys with a uniformly distributed minority phase are a potential substitute for the materials applied in the manufacture of electric contactors and wear-resistant automotive components.Understanding the evolution of various microstructures of immiscible alloys and its correlation with their wear behavior is crucial for their industrial applications.Owing to the liquid-phase separation characteristics of binary Cu-Co and ternary Cu-Co-Fe immiscible alloys,segregation occurred or even a layered microstructure was formed by using conventional casting methods,and obtaining a uniform microstructure was difficult,which seriously limited their applications.This study presents a new strategy for inhibiting the liquid-phase separation and improving the properties of immiscible alloys.Under a high magnetic field,the microstructure of an undercooled alloy was changed,affecting its wear behavior.The experimental results reveal that the microstructures of Cu_(50)Co_(50)and Cu_(52)Co_(24)Fe_(24)alloys showed dendritic morphology at modest undercooling without a magnetic field,while the microstructure of Cu_(50)Co_(50)alloy exhibited a core-shell structure and Cu_(52)Co_(24)Fe_(24)alloy exhibited an eccentric core-shell structure under large undercooling.Moreover,the application of a high magnetic field resulted in the more uniform microstructure of Cu_(52)Co_(24)Fe_(24)alloy.With the application of a high magnetic field,the second phases generated by the phase separation of Cu_(50)Co_(50)and Cu_(52)Co_(24)Fe_(24)alloys were elongated parallel to the magnetic field direction,and the size of second phases in the alloys decreased significantly in the perpendicular field direction,however,the microstructures of the Cu_(52)Co_(24)Fe_(24)alloy showed a more uniform distribution.Specimens with large undercoolings in Cu_(50)Co_(50)and Cu_(52)Co_(24)Fe_(24)alloys exhibited excellent wear resistance reg

关 键 词：难混溶合金 凝固 强磁场 摩擦 

分 类 号：TG146[一般工业技术—材料科学与工程]