pulbriosakestest või kiududest moodustunud poorne ruumiline struktuur; komposiitmaterjali saamiseks täidetakse karkassi poorid teise faasiga, nt infiltreerimise teel vedelmetalliga (vt poorne materjal), the compacted powder matrix consisting of a network of solid particles or grains; it provides a system of interconnected pores and channels of a size range that permits inimpeded capillary force action throughout the infiltration process (see: cellular material)