Open AccessEffect of particle size of Y2O3-Al2O3 additives on microstructure and mechanical properties of Si3N4 ceramic balls for bearing applications
Author(s) -
Jing Zhang,
Wenxue Wang,
Feng Sun,
Weiru Zhang,
Boheng Li,
Mingshuai Zhang
Publication year - 2021
Publication title -
processing and application of ceramics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.326
H-Index - 15
eISSN - 2406-1034
pISSN - 1820-6131
DOI - 10.2298/pac2103297z
Subject(s) - materials science , ceramic , microstructure , sintering , relative density , composite material , weibull modulus , fracture toughness , particle size , elastic modulus , agglomerate , dispersion (optics) , vickers hardness test , toughness , chemical engineering , physics , optics , engineering
Si3N4 ceramic balls were prepared by gas pressure sintering with Y2O3 and Al2O3 as sintering additives. The effects of particle size of Y2O3-Al2O3 additives on densification, microstructure and mechanical properties of Si3N4 ceramic balls were investigated. The reliability of Si3N4 ceramic balls was evaluated through the Weibull modulus. The results showed that Si3N4 ceramic balls containing nanosized Y2O3-Al2O3 additives have a higher relative density and better comprehensivemechanical properties compared with the samples containing microsized additives, with relative density of 98.9 ? 0.2%TD, Vickers hardness of 14.7 ? 0.1GPa, indentation fracture toughness of 6.5 ? 0.1MPa?m1/2 and crushing strength of 254 ? 8.5MPa. The more homogeneous and extensive dispersion of the nanosized sintering additives in the Si3N4 matrix is the main reason for the enhancement in density and mechanical properties of the Si3N4 ceramic balls.