Method for preparing porous heat conduction copper pipes through powder extrusion forming technology

A technology of extruding and heat-conducting copper tubes, which is applied in the field of powder metallurgy injection molding, can solve the problems of lack of porosity and difficulty in ensuring the uniform distribution of copper powder, etc., and achieve the effect of compact appearance and broad application prospects

Inactive Publication Date: 2016-01-20
SHENZHEN ELEMENT TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Due to the high friction between the copper powder and the tube wall, this process is not suitable for porous copper tubes with a large aspect ratio.
In addition

Method used

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  • Method for preparing porous heat conduction copper pipes through powder extrusion forming technology

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] Add 45vol.% polymer binder (50wt.% paraffin, 45wt.% polyethylene and 5wt.% stearic acid) to the copper powder with a particle size D50 of 45 μm, in the internal mixer In the process, the metal powder is first heated to 160°C, and then polyethylene, paraffin and stearic acid are gradually added. After mixing evenly, the granular feed is made by a granulator. It was shaped by an extruder at 130°C to produce a tubular green body (inner diameter? 16mm, outer diameter? 20mm), and then the tubular green body was cut into a length of 300mm. Soak the green body in a n-hexane solution at 40°C and keep it warm for 24 hours to degrease the solvent. Then take out the green body, put it into the degreasing sintering furnace after drying. Pass flowing argon into the debinding sintering furnace, and remove the remaining binder by thermal debinding at 450°C. Then the temperature was gradually raised to 750°C, and the temperature was lowered after sintering for 1 hour. Finally, a po...

Embodiment 2

[0029] Add 55vol.% polymer binder (86wt.% polyoxymethylene, 6wt.% polyethylene, 6wt.% ethylene-vinyl acetate copolymer and 2wt. % stearic acid), first heat the metal powder to 180°C in an internal mixer, and then gradually add polyoxymethylene, polyethylene, ethylene-vinyl acetate copolymer and stearic acid. After mixing evenly, the granular feed is made by a granulator. It was shaped by an extruder at 175°C to produce a tubular green body (inner diameter? 10mm, outer diameter? 16mm), and then the tubular green body was cut into a length of 500mm. The green body is degreased with oxalic acid in a degreasing furnace. Then put into the degreasing sintering furnace. Pass flowing argon into the debinding sintering furnace, and remove the remaining binder by thermal debinding at 450°C. Then the temperature was gradually raised to 700°C, and the temperature was lowered after sintering for 1 hour. Finally, a porous copper tube with a porosity of 48% was obtained.

Embodiment 3

[0031] Add 50vol.% polymer binder (50wt.% paraffin, 40wt.% polyethylene and 10wt.% stearic acid) to the copper powder with a particle size D50 of 10 μm. In the process, the metal powder is first heated to 160°C, and then polyethylene, paraffin and stearic acid are gradually added. After mixing evenly, the granular feed is made by a granulator. It is shaped by an extruder at 180°C to produce a tubular green body (inner diameter? 16mm, outer diameter? 20mm), and then the tubular green body is cut into a length of 300mm. Soak the green body in a solution of n-heptane at 40°C and keep it warm for 24 hours to carry out solvent degreasing. Then take out the green body, put it into the degreasing sintering furnace after drying. Pass flowing argon into the debinding sintering furnace, and remove the remaining binder by thermal debinding at 450°C. Then the temperature was gradually raised to 750°C, and the temperature was lowered after sintering for 2 hours. Finally, a porous coppe...

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Abstract

The invention belongs to the field of powder metallurgy, and particularly discloses a method for preparing porous heat conduction copper pipes through the powder extrusion forming technology. The method includes the steps that firstly, feedstock preparation is conducted, wherein a macromolecule binding agent and copper powder are evenly mixed in an internal mixer, and then feedstock uniform in structure is obtained through granulation; secondly, extrusion forming and cutting are conducted, wherein the feedstock is added to a single-screw extruder, and tubular green blanks are extruded out and then cut into the required length; thirdly, degreasing is conducted, wherein degreasing is conducted on the green blanks through a solvent degreasing or catalysis degreasing method; and fourthly, sintering is conducted, wherein thermal degreasing is conducted under negative pressure through a degreasing sintering furnace according to a carrier gas degreasing method, and then samples are heated and sintered in protection atmosphere to obtain the porous heat conduction copper pipes. The advantages of the plastic extrusion forming technology and the powder metallurgy technology are combined in the method, and the porous heat conduction copper pipes with the porosity of 20% to 50% can be efficiently produced on a large scale.

Description

technical field [0001] The invention belongs to the field of powder metallurgy injection molding, and in particular relates to a method for preparing porous heat-conducting copper pipes by using powder extrusion molding technology. Background technique [0002] Thermally conductive copper tubes have high thermal conductivity and corrosion resistance, and are widely used in air conditioners, refrigerators, and heat dissipation elements of electronic components. At present, copper pipes are generally obtained by direct hot extrusion of copper profiles or continuous casting. Chinese patent (Application No.: 200510017984.5) obtains copper tubes with a red surface by hot extrusion of copper profiles at 600-860 °C, and then through pickling and bright annealing processes. The Chinese patent (application number: 200710065281.9) melts the copper alloy at 1150~1300°C, and then manufactures precision pipes by continuous casting. [0003] The above methods can only produce dense pipe...

Claims

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Application Information

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IPC IPC(8): B22F3/20
Inventor 余鹏吕永虎顾道敏
Owner SHENZHEN ELEMENT TECH CO LTD
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