This article explored the relationship between structure and thermal conductivity in additively manufactured interpenetrating A356/316L stainless steel composites. The thermal conductivities were determined using the transient plane source (TPS) method. The thermal conductivity of a 43 vol% 316L composite was found to be 53 W/mK. This was a much lower value than what was predicted by the rule of mixtures approximation. This was believed to happen because residual porosity degrades ...