Pressureless sintering of Al2O3/Ni nanocomposites
Journal
Journal of the European Ceramic Society
Journal Volume
19
Journal Issue
4
Pages
463-468
Date Issued
1999
Author(s)
Abstract
In the present study, an Al2O3/Ni nanocomposite containing 5vol% Ni is prepared by pressureless sintering at 1400°C for 2h. Most nickel inclusions, around 70% in the sintered nanocomposite, locate at the intergranular sites, the triple junctions and Al2O3/Al2O3 grain boundaries. The average size of the nickel inclusions at the triple junctions, grain boundaries and intragranular locations is 145, 131 and 73nm, respectively. The average size of all nickel inclusions is 118nm. The presence of nickel inclusions can prohibit the grain growth of matrix grains. The size of Al2O3 grains in the sintered nanocomposite is only 490nm. The strength of the nanocomposite is thus high for the refined microstructure. The matrix Al2O3 grains and Ni inclusions at triple junctions underwent considerable coarsening during a post-annealing treatment at 1300°C for 2h. The strength of the annealed composites is thus reduced significantly after annealing.
Subjects
Al2O3; Microstructure-final; Nanocomposites.; Sintering; Strength
Other Subjects
Alumina; Annealing; Crystal microstructure; Grain boundaries; Grain growth; Grain size and shape; Nanostructured materials; Nickel; Sintering; Strength of materials; Nanocomposites; Post annealing treatment; Pressureless sintering; Triple junctions; Ceramic matrix composites
Type
journal article