摘要
为进一步推动中/高熵金属间化合物的工程化应用,以FeCoNi_(2)Al中熵金属间化合物为研究对象,制备了16 kg级大尺寸合金铸锭,细致研究和分析了铸态合金显微组织和力学性能,并采用熔模精密铸造技术浇注了特征结构元件,评价了合金的铸造工艺性能。结果表明,大尺寸FeCoNi_(2)Al中熵金属间化合物铸锭具有良好的成分均匀性,铸态合金由具有树枝状形貌的B2初生相和枝晶间具有片层结构的L1_(2)+B2相共晶组织构成,室温下铸态合金抗拉强度达1115 MPa,伸长率为4.6%,650℃下合金抗拉强度为434 MPa,伸长率可达14.6%,FeCoNi_(2)Al中熵金属间化合物熔体的流动性低于TC4合金,优于TiAl-4822合金。当特征结构元件壁厚为2 mm时,板状试样出现欠铸且内部存在大量缩松型铸造缺陷,熔体以端部固相质点聚集堵塞为主的方式停止流动。相关研究结果为中/高熵金属间化合物熔模精铸成形工艺优化和工程化应用奠定一定技术基础。
To further promote the industrial application of medium/high entropy intermetallics,a bulk of FeCoNi_(2)Al medium entropy intermetallic ingot with 16 kg as the research object was prepared in this study.Microstructure and mechanical properties of the as-cast alloy were studied and analyzed in detail.Moreover,characteristic structural components were obtained via investment casting route,by which the forming performance of the alloy was evaluated.Results show that the FeCoNi_(2)Al medium entropy intermetallic ingot has good composition uniformity.The as-cast alloy is composed of B2 primary phase with dendritic morphology and interdendritic L1_(2)+B2 phase eutectic structure with lamellar morphology.The tensile strength of the as-cast alloy is 1115 MPa at room temperature,and the elongation is 4.6%.At 650℃,the tensile strength of the as-cast alloy is 434 MPa,and the elongation can reach 14.6%.Melt fluidity of the FeCoNi_(2)Al medium entropy intermetallic is lower than that of TC4 alloy but better than that of TiAl-4822 alloy.When the thickness of the characteristic structural component is 2 mm,the plate casting is incompletely filled and a mass of shrinkage porosity is formed within the casting.Moreover,the cessation mechanism of flow for the molten alloy is due to the accumulation of solid particles at the tip of flow.Results of this research will lay a certain technical foundation for the casting process optimization and industrial application of medium/high entropy intermetallics.
作者
高威
宗骁
孔凡涛
张凤祥
丁贤飞
南海
GAO Wei;ZONG Xiao;KONG Fantao;ZHANG Fengxiang;DING Xianfei;NAN Hai(AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China;Beijing Institute of Aeronautical Materials Co.,Ltd.,Beijing100094,China;Beijing Engineering Research Center of Advanced Titanium Alloy Precision Forming Technology,Beijing 100095,China;School of Materials Science and Engineering,HarbinInstitute of Technology,Harbin 150001,China)
出处
《材料工程》
EI
CAS
CSCD
北大核心
2024年第1期175-182,共8页
Journal of Materials Engineering
基金
国家自然科学基金项目(51971074)
中国航发集团自主创新专项基金项目(CXPT-2020-007)。
关键词
中/高熵合金
金属间化合物
熔模精密铸造
共晶组织
力学性能
medium/high entropy alloy
intermetallic
investment casting
eutectic microstructure
mechanical property
