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Spark Plasma Sintering of Magnesia‐Doped Alumina with High Hardness and Fracture Toughness
Author(s) -
Chakravarty Dibyendu,
Bysakh Sandip,
Muraleedharan Kuttanellore,
Rao Tata Narasinga,
Sundaresan Ranganathan
Publication year - 2008
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2007.02094.x
Subject(s) - spark plasma sintering , materials science , fracture toughness , grain size , sintering , toughness , composite material , doping , magnesium , metallurgy , grain boundary , microstructure , optoelectronics
The effect of grain size of magnesia and its content as well as spark plasma sintering conditions on the density, grain size, strength, hardness, and toughness of alumina was investigated. Spark plasma sintering conditions were optimized at 1150°C/5 min/175°C/min. Addition of 100 nm magnesia gave higher density levels (99.5%), while better strength (600 MPa), hardness (25 GPa), and fracture toughness (4.5 MPa·m 1/2 ) were obtained with 15 nm magnesia. The good strength and hardness is attributed to the submicrometer grain size of the matrix, and the improved toughness to the presence of Mg‐rich nanoparticles and nanopores at grain boundaries.