Heat pipe and method of producing the same
A heat pipe ( 50 ) and a method ( 100 ) of producing the heat pipe are disclosed. The method includes the following steps: (1) inserting a mandrel ( 10 ) into a hollow metal casing ( 20 ) with a porous structure ( 30 ) combined to an outer surface of the mandrel; (2) filling powders ( 40 ) into a space formed between the hollow metal casing and the porous structure; (3) sintering the filled powders; (4) drawing the mandrel out of the hollow metal casing; and (5) sealing the hollow metal casing with a working fluid filled therein. The heat pipe produced by this method includes a composite wick structure ( 60 ) arranged in the hollow metal casing. By using this method, the mandrel can be easily drawn out of the hollow metal casing after the filled powders are sintered.
1. A method of producing a heat pipe comprising the steps of:
inserting a mandrel into a hollow metal casing with a porous structure combined to an outer surface of the mandrel;
filling powders into a space formed between the hollow metal casing and the porous structure;
sintering the filled powders;
drawing the mandrel out of the hollow metal casing, leaving the porous structure combined with the sintered filled powders in the hollow metal casing; and
sealing the hollow metal casing with a working fluid filled therein.
2. The method of claim 1 , wherein the porous structure includes a mesh made by weaving a plurality of flexible wires together.
3. The method of claim 2 , wherein the mesh has a rough surface to contact with the outer surface of the mandrel.
4. The method of claim 1 , wherein the porous structure is formed of a metal sheet with a plurality of holes therein.
5. The method of claim 1 , wherein the porous structure is combined to the mandrel before the mandrel is inserted into the hollow metal casing.
6. The method of claim 1 , wherein the powders are made of a metal of one of copper, aluminum, silver and nickel.
7. The method of claim 1 , wherein the powders are made of ceramic material.
8. A heat pipe made by a method comprising the steps of:
inserting a mandrel into a hollow metal casing with a mesh attached on an outer surface of the mandrel;
filling powders into a space formed between the hollow metal casing and the mesh;
heating the hollow metal casing, powders, mesh and mandrel at a temperature that the powders are sintered and connected with the mesh;
drawing the mandrel out of the hollow metal casing, leaving the mesh combined with the sintered filled powders in the hollow metal casing;
injecting liquid in the hollow metal casing;
pumping air out of the hollow metal casing; and
sealing the hollow metal casing.
9. The heat pipe of claim 8 , wherein the sintered powders have a capillary force larger than that of the mesh.
10. The heat pipe of claim 8 , wherein the mesh has a liquid permeability higher than that of the sintered powders.
11. The heat pipe of claim 8 , wherein the mesh is formed of a plurality of wires, and the powders each have a diameter which is smaller than a diameter of each of the plurality of wires forming the mesh.