High-Strength FeCrMo0.2(AlNi)0.5 High Entropy Alloy Strengthened by B2 Precipitate

The purpose of this study is to investigate the effects of Al and Ni addition on the microstructure and mechanical properties of FeCrMo0.2 alloy. The FeCrMo0.2 alloy displayed a disordered BCC solid solution structure. With the addition to Al and Ni elements, an ordered peak around 30.6° appeared in FeCrMo0.2(AlNi)0.5 alloy. A uniform microstructure was obtained in FeCrMo0.2 alloy while dense nano-scale or micron-scale particles precipitated in FeCrMo0.2(AlNi)0.5 alloys. Besides, with the addition to Al and Ni elements, the yield strength increased from 550 to 1600 MPa while the plastic strain ep decreased to 30%. And the Vickers hardness increased from HV380 to HV522. The strengthening mechanisms in the alloy system were the solid solution strengthening and the second-phase strengthening.