Effect of initial powder particle size on densification behavior and mechanical properties of laser additive manufacturing of AlCoCrFeNi2.1 eutectic high-entropy alloy

Abstract

The AlCoCrFeNi2.1 eutectic high-entropy alloys (EHEAs) were prepared by selective laser melting (SLM) with powders of different particle sizes as variables. The spreading process of powders with different particle sizes and the effect of particle size on densification behavior, phase and mechanical properties were studied. The maximum densification of the D5016 sample is 99.58%, while that of D5035.8 is 99.1%. For the D5016 system, the BCC/B2 phase of the powder is transformed into the FCC phase of the SLM product, while the reverse is true for the D5035.8. The microhardness of SLM-printed coarse powder samples is higher than that of fine powder by more than 100 HV, and the microhardness of X-Y plane is about 20–40 HV higher than that of X-Z plane. The compressive strength and plasticity of the D5016 sample are 300 MPa, 8% (⊥BD) and 60 MPa, 9% (∥BD) higher than that of D5035.8.