Process to manufacture a metal foam provided with channels and metal foam thus produced

Abstract

A manufacturing process for a metal foam provided with at least one channel and intended namely for the manufacture of heat exchangers using a preform of balls. A foundry core constituted by a central core and a coating of a material fusible at low temperature are arranged in a foundry mould, the preform is then tightly arranged around the core, the fusible material is then eliminated by heating at a low temperature, then the molten metal mass is cast in the mould in order to fill the free spaces between the balls and between the balls and the central core, and lastly the balls are eliminated.

1 . A manufacturing process for a metal foam provided with at least one channel and intended namely for the manufacture of heat exchangers using a preform of balls, wherein a core constituted by a central core and a coating of a material fusible at low temperature are arranged in a foundry mould, the preform then tightly arranged around the core, the fusible material is then eliminated by heating at a low temperature, then the molten metal mass is cast in the mould in order to fill the free spaces between the balls and between the balls and the central core, and lastly the balls are eliminated. 
     
     
         2 . A process according to  claim 1 , wherein the channel is constituted, after the metal mass has been cast, by the metal mass replacing the wax coating. 
     
     
         3 . A process according to  claim 1 , wherein the central core or the core is formed by ceramic, steel, sand, a soluble material or a material identical to that forming the preform. 
     
     
         4 . A process according to  claim 1 , wherein the core is formed of three elements, a first element constituted by the ceramic, steel or sand central core, a second element constituted by a peripheral layer of refractory material and a third element constituted by a coating of material fusible at low temperature. 
     
     
         5 . A process according to  claim 1 , wherein the core is formed of four elements, a first element constituted by a ceramic, steel or sand central core, a second element constituted by a peripheral layer of a refractory material, a third element constituted by a layer of ceramic material and a fourth element constituted by the coating of material fusible at low temperature. 
     
     
         6 . A process according to  claim 1 , wherein the central core is rectilinear. 
     
     
         7 . A process according to  claim 1 , wherein the central core has curves. 
     
     
         8 . A process according to  claim 1 , wherein the central core is tubular. 
     
     
         9 . A process according to  claim 1 , wherein the low temperature fusible material is a wax. 
     
     
         10 . A process according to  claim 1 , wherein the coating has continuous or discontinuous protrusions on its inner surface. 
     
     
         11 . A metal foam obtained by following the process according to  claim 1  and provided with at least one channel. 
     
     
         12 . The metal foam according to  claim 11 , wherein the channel is in the form of a rectilinear or curved tube. 
     
     
         13 . The metal foam according to  claim 11 , wherein the channel and foam are made of aluminium or aluminium alloy.