Influence of in-situ Al2O3 content on mechanical properties of Al2O3 reinforced Fe–Cr–Ni alloys

Abstract

AbstractIn-situ Al2O3 (14.8–31.3 wt.%) reinforced Fe–Cr–Ni alloys were prepared using reactive hot pressing at a temperature of 700°C and pressure of 30 MPa for 2 h. X-ray diffraction showed that the obtained metal matrix composites (MMCs) mainly comprised Al2O3, Fe–Cr and Cr0.7Fe0.36Ni2.9 phases. Vickers hardness values of the composites with varying Al2O3 contents were all around 4.28 GPa. Scanning electron microscopy images showed that the Al2O3 particles in the MMCs (with Al2O3 content of 14.8 wt.%) were ultrafine and uniformly distributed. Moreover, the metal matrix composite with 14.8 wt.% Al2O3 exhibited the highest values of fracture toughness and bending strength, which were 15.2 MPa · m1/2 and 529 MPa, respectively.