Structure investigation of AlFeNiTiZn nanocrystalline high entropy alloy

• Published in: Vacuum 2023-04, Vol.210, p.111878, Article 111878
• Main Authors: Kalantari, Helia, Khayati, Gholam Reza, Adeli, Mandana
• Format: Article
• Language: English
• Subjects: High energy planetary ball mill; High entropy alloy; Johnson–mehl–avrami model; Kinetics; Sintering process
• ISSN: 0042-207X; 1879-2715
• DOI: 10.1016/j.vacuum.2023.111878

The AlFeNiTiZn high entropy alloy with a mean crystallite size of 35–45 nm was synthesized within a two-stage process. Firstly, as a powder form using a planetary ball mill in an argon atmosphere and after that compressed the powder samples and sintered them in tube furnace as bulk samples. The X-ray diffraction, scanning electron microscopy and transmission electron microscopy techniques were used to examine the structural and morphological changes during the process. The two-phase solid solution (FCC + BCC) was formed after mechanical alloying. In addition to FCC + BCC, gahnite (ZnAl2O4) was synthesized after sintering. A differential scanning calorimetry analysis has also confirmed that recrystallization took place at 311 °C. Nucleation and growth were adequate explanations for the mechanochemical synthesis of the AlFeNiTiZn high entropy alloy based on Johnson-Mehl-Avrami model. An interface-controlled growth was the conversion mechanism based upon the Avrami exponent. According to a vibrating sample magnetometer, both as-milled and as-sintered alloys have semi-hard magnetic properties with 37.42 and 25.43 emu/g saturation magnetization, respectively. In sintered HEA, the microhardness was measured to be about 724 ± 15 HV. •AlFeNiTiZn HEAs manufactured by mechanical alloying and sintering process.•The preparation of HEA including nanocrystalline structures of FCC and BCC.•Bulk fabrication of HEA using FCC, BCC, and intermetallic phases.•Determination of mechanism of HEAs formation by JMA model.•Investigation of mechanical and magnetic properties of prepared HEAs.