LAUSR

Metal foams with high melting points are generally fabricated by the space holder technique. Foams with desirable pore size, shape and distribution can be obtained by using appropriate space holder. However, porosity ( P ) is always not equal to spacer content ( ϕ mac ), which makes it difficult to obtain the expected porosity. In this study, a model equation for describing the relationship between P and ϕ mac was established based on theory, i.e., P  = ( a 1 ϕ mac  +  a 2 )/( a 3 ϕ mac  +  a 4 ). Each coefficient a i (i.e., a 1 , a 2 , a 3 , a 4 ) could be determined by the porosity of cell walls ( P cell wall ) and the volume change rate of macropores ( R mac ). The theoretical equation was in accordance with the experimental results by authors and in the studies. It implies that P cell wall and R mac can be considered as constants in one certain production condition.