Effect of oxide nanoparticles on the mechanical properties of novel cobalt-free FeCrNi medium entropy alloys

摘要

A series of oxide dispersion strengthened (ODS) FeCrNi medium entropy alloys (MEAs) were fabricated via mechanical alloying and spark sintering plasma (SPS). The ODS FeCrNi MEAs are mainly composed of fcc matrix, in which Y-Ti-O typed nanoparticles are uniformly distributed. Effects of TiH2 and YH3 additions on the mechanical properties were investigated. Increasing the addition of TiH2 and YH3 leads to the significantly enhanced strength while slightly decreased ductility. The optimized combination of yield strength (1024 MPa) and fracture elongation (12.4%) is obtained in the alloys with the addition of 0.2 wt% TiH2 and 0.2 wt% YH3. The high strength is mainly ascribed to the highly dispersed oxide nanoparticles and ultrafine-grained grains.