Evaluation of microstructural and mechanical properties of AlxCrFeMnNi high entropy alloys

• Main Authors: Masemola, Khumo, Malatji, Nicholus, Patricia Popoola, A.
• Format: Conference Proceeding
• Language: English
• Subjects: AlxFeNiCrMn; Compressive strength; High entropy alloys; Microhardness and annealing
• ISSN: 2214-7853; 2214-7853
• DOI: 10.1016/j.matpr.2019.12.320

The aim of this work is to investigate microstructural and mechanical properties of the AlxFeNiCrMn HEAs fabricated by arc-melting method followed by annealing at 1000 °C in air. Microstructural features and phase formation of the developed alloy were examined using scanning electron microscope (SEM) and X-ray diffraction (XRD) respectively. The microhardness and compressive strength measurement were performed with a diamond base indenter and Instron compression machine. It was noticed that Al addition encouraged the formation of dendrites in the alloys with dendritic cores and interdendritic regions. The microhardness decreased from 495 HV to 397 HV with increasing Al concentration. Adjusting the Al content above 10 at% increased the ultimate strength from 1200 MPa to 1429 MPa. However, ductility was reduced which significantly lowered the total elongation by around 5%. The alloy with x = 15, displayed a good combination of high strength and ductility due to a reasonable balance in the volume fraction of BCC and FCC solid solution phases. The addition of Al is beneficial to the mechanical performance of the AlxFeNiCrMn alloy, but inadequate amounts will be counterproductive.