Al含量对激光沉积(CoCrFeNi)-Al高熵合金晶粒形貌的影响
Effect of Al Content on Grain Morphology of Laser Deposited(CoCrFeNi)-Al High Entropy Alloys
王文慧 1唐延川 1王友星 1万能1
作者信息
- 1. 华东交通大学 材料科学与工程学院,江西 南昌 330013
- 折叠
摘要
激光沉积技术有望成为制备高熵合金的理想方法,但其制备的高熵合金易产生粗大柱状晶组织,限制了其在高熵合金制备中的广泛应用.利用激光沉积制备了(CoCrFeNi)1-xAlx(x=0,0.10,0.15,0.20)高熵合金,研究了不同Al含量下激光沉积(CoCrFeNi)1-xAlx高熵合金物相及晶粒形貌的演变规律,利用差热分析法对不同Al含量下高熵合金的凝固行为进行了分析.结果表明:随Al含量的增加,激光沉积(CoCrFeNi)1-xAlx高熵合金物相由面心立方(FCC)单相转变为FCC和体心立方(BCC)双相结构,不同Al含量下高熵合金中BCC相含量分别为 3vol%(x=0.10)、24vol%(x=0.15)和 52vol%(x=0.20);激光沉积高熵合金组织形貌也随Al含量增加由粗大柱状晶转变为细长晶粒,晶粒尺寸由 116 μm(x=0)显著降低至 40 μm(x=0.20).这主要是由于Al含量的增加可降低(CoCrFeNi)1-xAlx高熵合金形核过冷度(ΔTN),并提高合金的生长限制因子(Q),从而产生更为显著的成分过冷,大幅促进了形核行为.
Abstract
Laser deposition technology is expected to be an ideal method for preparing high entropy alloys(HEAs).However,the HEAs prepared by laser deposition prefer to present the microstructure of coarse columnar grains,which limits the wide application of laser deposition in preparing HEAs.(CoCrFeNi)1-xAlx(x=0,0.10,0.15,0.20)HEAs were prepared by laser deposition.The evolution of phase and grain morphology of laser deposited(CoCrFeNi)1-xAlx HEAs were studied.The solidification behavior of the HEAs was analyzed by differential thermal analysis.The results show that with the increase of Al content,the phase of laser deposited(CoCrFeNi)1-xAlx HEAs changes from face centered cubic(FCC)single phase to FCC and body centered cubic(BCC)dual phase structure.The content of BCC phase in the HEAs with different Al contents is 3vol%(x=0.10),24vol%(x=0.15)and 52vol%(x=0.20),respectively.With the increase of Al content,the grain morphology of the laser deposited HEAs also changes from coarse columnar grains to fine elongated grains,and the grain size decreases significantly from 116 μm(x=0)to 40 μm(x=0.20).This can be owing to the decrease in nucleation undercooling(ΔTN)and the increase of growth restriction factor(Q)of(CoCrFeNi)1-xAlx caused by the increase of Al content,which can promote more significant constitutional undercooling and boost the nucleation behavior.
关键词
激光沉积/高熵合金/形核过冷度/生长限制因子/晶粒尺寸Key words
laser deposition/high entropy alloy/nucleation undercooling/growth restriction factor/grain size引用本文复制引用
基金项目
江西省自然科学基金项目(20202ACBL214015)
江西省自然科学基金项目(20181BAB216003)
出版年
2024
NETL
NSTL
万方数据