Method for mixing powdered metal and nanocarbon material, and method for manufacturing nanocarbon/metal composite material

Abstract

A manufacturing method is provided to be used in place of a conventional mechanical alloying method. A powdered metal and a nanocarbon material are placed in an empty metal mill vessel containing no balls, and a mixture in which the powdered metal is coated with this nanocarbon material is obtained by shaking in three dimensions.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a method for mixing a powdered metal and a nanocarbon material, and to a method for manufacturing a nanocarbon / metal composite material. BACKGROUND OF THE INVENTION [0002] In recent years, special carbon fibers known as “carbon nanofibers” have attracted attention. Carbon nanofibers have a configuration in which sheets of carbon atoms arranged in the form of a hexagonal network are rolled up into a tubular form; such nanofibers have a diameter of 1.0 nm to 150 nm, and a length of a few micrometers to 100 μm. Since such fibers have a nano-size diameter, they are referred to as “carbon nanofibers,”“carbon nanotubes,” or the like (such materials will be called “nanocarbon materials” below). [0003] These nanocarbon materials are reinforcing materials, and are also materials with a good thermal conductivity. Accordingly, strength and thermal conductivity can be improved by mixing these materials with metal materials. [0004] I...

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Benefits of technology

[0013] In the aforementioned method for manufacturing a nanocarbon / metal composite material, since no balls are placed in the vessel, there is no danger that the nanocarbon material will be excessively broken up. Furthermore, the nanocarbon material can be bonded to the powdered metal by shaking the mill vessel in three dimensions. Accordingly, the nanocarbon material in the form of long fibers can be mixed with the powdered metal in a desirable manner. In addition, in the method of the present invention, a sintered body, i.e., a nanocarbon / metal composite material can be obtained by sintering the uniformly mixed mixture of a powdered metal and nanocarbon material. Since the nanocarbon material is uniformly mixed with the powdered metal, a nanocarbon / metal composite material which has a large strength and a large thermal conductivity can be manufactured.

[0014] The nanocarbon material that is prepared in the aforementioned preparatory step is preferably a nanocarbon material that has been dispersed by ultrasound in advance. If a nanocarbon material that has thus been dispersed by ultrasound is used, a nanocarbon / metal composite material in which the nanocarbon material is more favorably dispersed can be manufactured.

Problems solved by technology

However, since the carbon nanotubes are mechanically broken up and converted into short fibers, no great improvement in thermal conduction can be expected.

However, in the case of short fibers, the thermal conductivity is small.

Thus, in conventional mechanical alloying methods, it has been ascertained that the desired thermal conductivity performance cannot be sufficiently obtained.

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