PURPOSE: To obtain a cold-accumulating material securing necessary air permeability without relating to the shape of the powder of the cold-accumulating material, etc., by pressing the mixture of the power of the cold-accumulating material with the power of a low melting point metal and subsequently baking the pressed power to melt out the low melting point metal.
CONSTITUTION: (A) The powder of a cold-accumulating material (e.g. Er3Ni) and (B) the power of a low melting point metal (preferably lead) for cold- accumulating freezers are mixed with each other, and pressed to form the pressed powder. The pressed power is baked to melt only the component B, thereby forming open-pores in the pressed powder. Concretely, e.g. the mixture of Er3Ni power with lead powder is charged in a second step displacer and in a mold having the same inner diameter, pressed by a hydranlic pressure of 0.3-6tons/cm2, and subsequently baked in an inert gas atmosphere over or in a vacuum oven at 650-800°C for 1-4 hr.
KOMURO AKIMITSU
ONDA JUNICHI
