摘要
为避免熔覆层及基体之间强韧性的突变,利用激光熔覆技术在Q235钢基体表面制备了CoCrFeMnNi/SiC梯度高熵合金涂层,通过X射线衍射、扫描电子显微镜、维氏硬度测试和摩擦磨损检测等方法,研究了SiC质量分数梯度变化对高熵合金涂层组织及性能的影响规律。研究结果表明:合理设定梯度涂层可以避免了每个亚层之间应力过于集中,使得试样每一亚层之间结合良好;CoCrFeMnNi为单一的FCC相,添加SiC陶瓷颗粒的CoCrFeMnNi高熵合金亚层中,出现了白色颗粒状析出物M_(7)C_(3)相;随着SiC陶瓷颗粒质量分数增加,CoCrFeMnNi/SiC高熵合金亚层中白色颗粒析出物增多且长大,而枝晶逐渐细化,气孔等缺陷明显减少;CoCrFeMnNi/SiC高熵合金涂层纵截面维氏硬度呈梯度变化,由基体向熔覆涂层表面递增,其表面的维氏硬度最高可达693.00;涂层的耐磨性与维氏硬度呈现相同变化规律,随着SiC质量分数的梯度递增,熔覆涂层的磨损量降低,耐磨性逐渐增强;CoCrFeMnNi高熵合金涂层的磨损机制以黏着磨损为主,伴随有磨粒磨损,而加入SiC陶瓷颗粒后,磨损表面出现更深的犁沟,逐渐以磨粒磨损为主。
In order to avoid the sudden change in the strength and toughness between cladding layer and substrate,the gradient coatings of CoCrFeMnNi/SiC high entropy alloy(HEA)were prepared on the surface of Q235 steel by laser cladding.The microstructure and wear properties of HEA coatings with different SiC mass fractions were investigated by X-ray diffraction,scanning electron microscopy,Vickers hardness testing and friction and wear testing.The results show that the bonding between each sub-layer of the samples is well combined due to the reasonable setting of the gradient coating which can avoid the excessive concentration of stress between each sublayer.CoCrFeMnNi alloy is single FCC phase structure,while white granular precipitate M_(7)C_(3)phase appears in CoCrFeMnNi HEA sub-layer with the addition of SiC ceramic particles.With the increase of SiC particles mass fraction,white precipitates in the CoCrFeMnNi/SiC HEA sub-layers grow up and increase,but the grain dendrites are gradually refined and the pores significantly decrease.Vickers hardness of the longitudinal section of CoCrFeMnNi/SiC HEA coatings show gradient change.Vickers hardness increases from the substrate to the surface of cladding and Vickers hardness of the surface can reach 693.00.The wear resistance of the coating shows the same law as the Vickers hardness.As the SiC particle mass fraction increases gradiently,the wear resistance of the cladding increases gradually,which shows that the wear loss decreases.The wear mechanism of CoCrFeMnNi HEA coating is mainly adhesive wear,accompanied by abrasive wear.However,after adding SiC ceramic particles,deeper grooves appeare on the wear surface,which is gradually dominated by abrasive wear.
作者
李晓峰
张泉
谢会起
冯英豪
杨晓辉
LI Xiaofeng;ZHANG Quan;XIE Huiqi;FENG Yinghao;YANG Xiaohui(School of Materials Science and Engineering,North University of China,Taiyuan 030051,China;State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China;Southwestern Institute of Physics,Chengdu 610225,China;College of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2021年第11期3835-3842,共8页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(52071299,51804280)
山西省重点研发计划(国际科技合作)项目(201903D421075)
山西省教育厅科技创新项目(2019L0556)
中北大学青年学术带头人支持计划项目(QX201802)。
关键词
激光熔覆
高熵合金
梯度结构
维氏硬度
摩擦磨损
laser cladding
high entropy alloys
gradient structure
Vickers hardness
friction and wear
