Structural parts of ceramics or metals can, in principle, be made by laser sintering
polymer coated ceramic or metal powders, followed by conventional methods for removing
the binder and sintering in ovens. Understanding the laser sintering of coated materials
requires knowledge of the behavior of beds containing composite particles. Many
correlations for predicting the effective thermal conductivity of a bed of solid particles exist
in literature, but little work has been done on beds of coated particles. We coated lead
shots(high conductivity) with a styrene acrylic acid copolymer (low conductivity) to study
the effect of coating thickness on the thermal conductivity. The thermal conductivity ofthe
coated particle·hed was found to •drop rapidly in the beginning·· and then level off with
increasing coating thickness. We also developed an equation that yields the equivalent
conductivity of a coated spherical particle subjected to axial heat flow. The predicted results
with the experimental measurements of bed conductivity obtained by an unsteady
state method.Mechanical Engineerin
