摘要 |
<p>A molten metal gas-atomizing spray-depositing apparatus has an atomizer which employs a pressurized gas flow for atomizing a stream of molten metal into a spray pattern of metal particles being initially hotter than the solidus temperature of the metal. The apparatus also has a substrate system which includes an outer substrate of metallic foil and an inner substrate for supporting the outer substrate. The outer foil substrate is movable relative to the metal particles in the spray pattern thereof and disposed below the atomizer for receiving on a surface of the foil a deposit of the particles in the spray pattern to form a product on the outer foil substrate. The outer foil substrate is of a thickness which is less than a predefined maximum thickness at which the capacity of the foil to absorb heat from the deposit is equal to the latent heat and super heat, if present, of the deposit. The foil thickness precludes reduction in temperature below the solidus temperature, and thereby complete solidification, of the metal particles forming the deposit upon initial contact with the foil surface whereby a reduction of porosity is achieved in the deposit.</p> |