Affiliation:
1. School of Materials Science and Engineering Hefei University of Technology Hefei 230009 P. R. China
2. Engineering Research Center of High Performance Copper Alloy Materials and Processing, Ministry of Education Hefei University of Technology Hefei 230009 P. R. China
3. National Key Laboratory of Marine Corrosion and Protection Luoyang 471023 P. R. China
4. School of Engineering Westlake University Hangzhou 310030 P. R. China
Abstract
Phase composition, microstructure, and mechanical properties of spark plasma sintered (SPSed) AlCrFeNiX (X = Co, Cu, and CoCu) high entropy alloys (HEAs) were investigated. The results show that gas‐atomized AlCrFeNiCo and AlCrFeNiCu HEAs exhibit the single body‐centered cubic (BCC) phase, while a dual‐phase (face‐centered cubic (FCC) + BCC) structure is observed in AlCrFeNiCoCu HEA. After spark plasma sintering, an FCC phase with different lattice parameters can be observed in all three HEAs except for the BCC phase. FCC1 phase enriched in Fe‐Cr and FCC2 phase enriched in Cu appear in SPSed AlCrFeNiCo and AlCrFeNiCu HEAs, respectively, while both FCC1 and FCC2 phases are precipitated in SPSed AlCrFeNiCoCu HEA. The SPSed AlCrFeNiCoCu HEA has the largest fraction of the FCC phase (33%), while the lowest fraction of the FCC phase (12%) is observed in the SPSed AlCrFeNiCu HEA. Furthermore, the brittle and hard σ phase is also precipitated in SPSed AlCrFeNiCo HEA. The SPSed AlCrFeNiCo HEA possesses the highest hardness of 465 HV and compressive yield strength of 1175 MPa, which is attributed to the high volume fraction of BCC phase and σ phase, while the SPSed AlCrFeNiCoCu HEA shows the lowest hardness of 363 HV and compressive yield strength of 1024 MPa due to the highest volume fraction of FCC phase.
Funder
Fundamental Research Funds for the Central Universities
National Natural Science Foundation of China