Effect of the addition of nano-Al2O3 on the microstructure and mechanical properties of twinned Al0.4FeCrCoNi1.2Ti0.3 alloys

• We prove the feasibility to elaborate Al0.4FeCr Co1.5NiTi0.3 high entropy alloy by MA + SPS.
• FCC phase Deformation twinnings occurred in Al2O3p-reinforced Al0.4FeCrCo1.5NiTi0.3 HEACs.
• The yield stress, fracture strength and plastic strain and Vickers hardness of obtained HEACs are as high as 2250 ± 10 MPa, 20.0 ± 0.50% and 743 ± 12Hv, respectively.

This manuscript reports the synthesis of nanoscale Al2O3-reinforced Al0.4FeCrCoNi1.2Ti0.3 high entropy alloy composites (HEACs) by mechanical alloying (MA) and spark plasma sintering (SPS). The effects of 12 wt% Al2O3 on the microstructure and mechanical properties were investigated. A major FCC phase along with BCC and Al2O3 were observed after SPS. Many deformation twinnings were found in HEACs from the SAED pattern. In the composite with 12 wt% Al2O3 quality fraction, the fracture strength, plastic strain and Vickers hardness of HEACs were as high as 2250 ± 10 MPa, 20.0 ± 0.50% and 743 ± 12Hv, respectively.