摘要
利用FeCoNiCr高熵合金为黏结相,并采用激光定向能量沉积(L-DED)方法制备新型75W-FeCoNiCr合金,研究激光线能量密度对合金相组成、相对密度、微观组织及力学性能的影响。研究结果表明,在线能量密度为157.14~325.00 J/mm时,不同线能量密度下的合金相组成没有明显变化,均由BCC-W相、TCP金属间化合物析出相Co_(7)W_(6)相和FCC-FeCoNiCr黏结相组成。随着线能量密度的增大,成分过冷度增加,析出相长大速率加快,其形态由板状/胞状向树枝晶状转变,并且粒径从1μm增加到8μm左右。随着线能量密度的升高,合金的致密度、显微硬度和压缩强度均呈现先升高后降低的趋势。当线能量密度为166.67 J/mm时,析出相主要为均匀胞状结构,此时,合金的致密度、显微硬度和压缩强度均达最高值,分别为98.4%、656 MPa和2261 MPa。
A new type of 75W-FeCoNiCr alloy was prepared by laser directed energy deposition(L-DED)using FeCoNiCr high entropy alloy as the bonding phase.The effects of laser line energy density on the phase composition,relative density,microstructure and mechanical properties of the alloy were discussed.The results show that in the range of linear energy density from 157.14−325.00 J/mm,the alloy phase composition has no obvious change at different linear energy densities,and all of them are composed of BCC-W phase,TCP intermetallic compound precipitation phase Co_(7)W_(6) and FCC-FeCoNiCr bonding phase.With the increase of linear energy density,the constitutional supercooling increases,the growth rate of the precipitated phase increases,its shape changes from plate/cell to dendrite,and its size increases from 1μm to about 8μm.With the increase of linear energy density,the density,microhardness and compressive strength of the alloy increase first and then decrease.When the linear energy density is 166.67 J/mm,the precipitated phase is mainly uniform cellular structure.At this time,the density,microhardness and compressive strength of the alloy reach the highest values,which are 98.4%,656 MPa and 2261 MPa,respectively.
作者
赵伟
韩勇
袁媛
黄丽婷
刘瑛
ZHAO Wei;HAN Yong;YUAN Yuan;HUANG Liting;LIU Ying(State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China;Zijin Mining New Energy and New Materials Technology(Changsha)Co.Ltd.,Changsha 410036,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2024年第8期3022-3031,共10页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(52371041)。
关键词
钨合金
高熵粘接相
激光定向能量沉积
线能量密度
熔池形貌
tungsten alloys
high-entropy binder phase
laser directed energy deposition
line energy density
melt pool morphology
