Effect of Porosity on the Tensile Strength of Sintered Compacts (III)

Abstract

The relationship between tensile strength and porosity in sintered compacts of low density was investigated. Porosity dependence of tensile strength in the low density range was shown in a modified form of the exponential type equation for the middle porosity range. Thus, the relationship between tensile strength and porosity can be represented by the following equations. For the low density range,
S=(m-nP) exp(-bP) (P₁<P≤P₀),
for the middle density range,
S=S₀ exp(-bP) (P₂<P≤P₁),
and for the high density range,
S=(S_s+kP^a) exp(-bP) (P%le;P₂),
where S is the tensile strength, P, the porosity, and S₀, S_s, a, b, k, m, n, P₀, P₁ and P₂, empirical constants.
The empirical constants were experimentally determined. The obtained equations for the low density range were as follows;
S=(62.3-197P) exp(-5.6P) [kg/mm²] (0.14<P≤0.23)
for sintered copper compacts, and
S=(281-1000P) exp(-3.7P) [kg/mm²] (0.24<P≤0.28)
for sintered iron compacts.