The outstanding tensile strength of Ni-rich high entropy superalloys fabricated by powder metallurgical process

Publication date: Available online 12 June 2019Source: Materials Chemistry and PhysicsAuthor(s): Byungchul Kang, Taeyeong Kong, Ho Jin Ryu, Soon Hyung HongAbstractThe present work reports the microstructure and tensile properties of a Ni-rich high-entropy superalloy (HESA; Ni46Co22Al12Cr8Fe8Ti3Mo1) having outstanding tensile properties, including yield strength of 1355 MPa and fracture elongation of 8.7 %. Powder metallurgical (PM) processes were used to fabricate the present HESA with homogeneous and fine-grained microstructure. A large number of γʹ precipitates were homogeneously distributed in a face-centered cubic (FCC) matrix. By using PM processes, a nanoscale grain size was achieved, and ultrafine TiC and Al2O3 dispersoids were uniformly formed within the FCC matrix. The outstanding mechanical properties of the HESA were attributed to the combined effect of grain boundary strengthening, solid solution strengthening, precipitate formation and dispersion strengthening.
Source: Materials Chemistry and Physics - Category: Materials Science Source Type: research