ZnO初期焼結体のネック半径

概要

論文の詳細を見る
First, sintering of two spheres of isotropic material which causes shrinkage is analyzed geometrically. The relation among the sphere radii, intersphere shrinkage and neck radius is expressed independently of ratio between the sphere radii. On the other hand, the larger ratio between sphere radii gives the larger selfexpansile pressure on the neck. Second, the sintering of crystallites of irregular shape as ZnO powder is considered within the initial stage, and P(γ_ρ) , the probability density of distribution of grain size γ_ρ and P(γ_n), that of neck radius γ_n are deduced statistically. If γ_ρ is given by the mean value of three elemental lengths independent of each other, P(γ_ρ) conforms to the x^2-distribution of 3 degrees of freedom and the average value γ^^-_ρ represents the distribution of γ_ρ. Because γ_n depends on the linear intergrain-shirinkage Δγ as well, P(γ_n) conforms to the x^2-distribution of 4 degrees of freedom. The average value γ^^-_n represents the distribution of γ_n Thus, the sintering of the actual grains can be equated to that of spheres of isotropic material with the same radius γ^^-_ρ which cause the relative shrinkage of Δ^^-_γ/γ^^-_ρ. Ultimately, γ^^-_n and P(γ_n) are derived from the observed values of γ^^-_ρ and the relative density of sintered bodies. Third, the major grains construct the skeleton of sintered body and merge the minor grains in openings among the major grains during sintering. The arrangement of major grains through which electric current flows hardly varies. The decrease in electric resistance as sintering progresses is caused by the growth in each neck radius and each grain size. The arguments as above support the process for Hamano et al. to derive the dependence of bulk resistivity on the neck radius from the experimental results.
社団法人日本セラミックス協会の論文
1988-11-01

ZnO初期焼結体のネック半径

スポンサーリンク

概要

著者

関連論文

スポンサーリンク