Thermal, elastic and mechanical properties of phosphate glass-ceramic-316 L stainless steel particulate composites, prepared by flash-pressing, have been measured. Results have then been explained using various theoretical models. It is shown that particles partly shrink away from the matrix on cooling; this is due both to the slight thermal mismatch between glass-ceramic matrix and 316 L stainless steel particles and to poor bonding between both phases. This small partial shrinkage could explain both the fracture characteristics and the fair agreement between theoretical and experimental values of elastic moduli.