A method to manufacture reticulated metal foam via a dual investment, includes pre-investment of a precursor with a diluted pre-investment ceramic plaster then applying an outer mold to the encapsulated precursor as a shell-mold.

A method for producing a casting by pouring a metal melt by gravity into a gas-permeable casting mold 1 having a cavity comprising at least a sprue 6, a runner 7 and a product-forming cavity 9, comprising pouring a metal melt into a desired cavity portion 10 including the product-forming cavity through the sprue, the melt being in a volume substantially equal to the volume of the desired cavity portion; supplying a gas 14 to the desired cavity portion through the sprue before the desired cavity portion is filled with the poured melt, so that the melt fills the desired cavity portion; and cooling a portion of the melt in contact with the gas directly or indirectly by water 16 supplied from outside the gas-permeable casting mold, simultaneously with, during or after supplying the gas, thereby solidifying the melt.

A method for producing a casting by pouring a metal melt by gravity into a gas-permeable casting mold 1 having a cavity comprising at least a sprue 6, a runner 7 and a product-forming cavity 9, comprising pouring a metal melt into a desired cavity portion 10 including the product-forming cavity through the sprue, the melt being in a volume substantially equal to the volume of the desired cavity portion; supplying a gas 14 to the desired cavity portion through the sprue before the desired cavity portion is filled with the poured melt, so that the melt fills the desired cavity portion; and cooling a portion of the melt in contact with the gas directly or indirectly by water 16 supplied from outside the gas-permeable casting mold, simultaneously with, during or after supplying the gas, thereby solidifying the melt.