多孔氧化铝陶瓷气孔率对强度的影响

Effect Porosity on Strength of Porous Alumina

加入不同量的碳粉作造孔剂,挤压成型、烧结,获得气孔率20％～55％的多孔氧化铝陶瓷。研究了气孔率及烧结程度对强度的影响。对试样的强度与气孔率按不同方程拟合.结果表明:当烧结程度较低时,强度（σ）与气孔率（ρ）的关系对经验方程σ=σ0（1-ρ）m的拟合结果最好;当烧结程度较高时,强度与气孔率的关系更符合经验方程σ=σ0exp（-bρ）。经验常数m,b,σ0与烧结程度有关。随着烧结程度的提高,这些值下降。

Porous alumina ceramics were obtained by preparing the specimens with various amounts of carbon powder used as pore-forming material. Samples of from 20% to 55% porosity were sintered. Effect of porosity and degree of specimen sintered on strength were investigated. It is show that the strength (σ) of specimens with changing porosity (ρ) can be represented by the empirical equation σ =σ0(1-ρ)m at low degree of specimens sintered or σ =σ0exp( - bρ)at high degree of specimens sintered. The empirical constants m,σ0 and b is dependent on the degree of specimens sintered. With increasing of the degree of specimens sintered, the value of m, σ0 and b decrease. The only method to obtain the specimens with high porosity and strength was by addition of pore - forming material not by decreasing degree of specimens sintered.