Abstract: A metal tube having an inner wall coated with a metal foam liner. The metal tube has an outer diameter of between 2 mm and 75 mm, a length of between 10 mm and 1000 mm, and a wall thickness of between 0.2 mm and 2 mm. The metal foam liner has a thickness of between 0.1 mm and 10 mm, a permeability of between 10?13 m2 and 10?8 m2, a capillarity radius of between 5 ?m and 1 mm and a thermo-conductivity of between 1 W/m·K and 50 W/m·K. Also, a method to obtain a metal tube which inner wall is metallurgically bonded in thermo-conduction with a metal foam liner, a method to obtain a metal tube with a heterogeneous metal foam liner, and a method to obtain a tubular metal foam liner 10a from a sheet of metal foam.

Abstract: An open cell porous material and a method for producing it is provided. The porous material of the present invention is generally composed of particles of at least one inorganic material bonded together by a brazing agent, generally provided as inorganic brazing alloy particles. The porous material is produced by heating a mixture comprising inorganic brazing alloy particles having a first melting temperature, inorganic particles having a second melting temperature higher than the first melting temperature, a binding agent having a decomposition temperature lower than the first melting temperature and preferably a foaming agent. In practice, the mixture is heated to induce foaming thereof via the foaming agent. The solid foamed structure is then heated at the decomposition temperature to substantially eliminate the binder.