Particle Size and the Mechanical Properties of Uganda Clay

Abstract

This paper describes a study of the effects of particle size on the porosity, microstructure, and mechanical properties of compacts fabricated under uniaxial compression with a rectangular die. Four ranges of different particle sizes were investigated to determine the dependence of fracture toughness; porosity and strength of the compacts on particle size. Thermal shock effects on the compacts were also investigated by determining the number of cycles to failure, when the compacts were cold shocked at four different temperatures. Compacts made from powders of larger particle size tended to have larger number of cycles to failure than those made of finer particle sizes. Contrary to this, compacts made from smaller particles size exhibited higher fracture toughness compared to those made from larger particle size.

Keywords:

• Cold shock
• Fracture toughness
• Microstructure
• Number of cycles to failure
• Strength
• Thermal shock

ACKNOWLEDGMENTS

The research is supported by Princeton University (Sam Kinyera Obwoya and Winston O. Soboyejo) and The Division of Materials Research of National Science Foundation (NSF DMR 0231418). The authors are grateful to the NSF Program Manager, Dr. Carmen, for the encouragement and support.

Notes

Table 4 showing values of the parameters m, B, and A corresponding to data in Table 3.

The new values of B and A shown in Table 5 are obtained when m is fixed at 18.3 and the curve fits in Fig. 9 is reworked backwards.