JP5052187B2 - Method for producing metal material and metal material - Google Patents

Description

  The present invention relates to a method for manufacturing a metal material, and more particularly to a method for manufacturing a metal material whose hardness is increased by mixing an additive into the metal material, and a metal material manufactured by this manufacturing method.

Conventionally, a technique for strengthening a metal material by mixing an additive having a size of several to several hundred nm with the metal material has been proposed. For example, in Patent Document 1, a metal material in which a Ti alloy is dissolved and fullerene or carbon nanotube (CNT) is mixed in a molten metal is used for a face portion of a golf club head. A technique that increases the strength and enables the thinning is described. Non-Patent Document 1 discloses that a composite material is obtained by mixing a powdered Al sample or Ti sample and a carbon nanotube powder by a triaxial vibration mill, performing hot pressing and then hot extrusion. It is described.
Japanese Patent Laid-Open No. 2002-778 Naoto Otake, Toru Kuzumaki, Yoshitaka Mitsuda, “Nanocarbon Composite”, Polymer, Japan Society for Polymer Science, December 2003, 52, p888-892

  However, there is a demand for higher strength from the industry for metal materials mixed with the above-described additives. However, the mechanical properties of the metal material mixed with the additive by the above-described method are not improved as expected from the properties of fullerene or the like as the additive, and further improvement is desired.

  In view of such circumstances, the present invention provides a method for producing a metal material that can further improve the hardness of the metal material and a method for producing the same in a method for producing a metal material that increases the hardness of the metal material by mixing an additive. An object of the present invention is to provide a metal material whose hardness is increased by the method.

  In the present invention, an additive comprising particles having a primary particle size of less than 0.5 μm is supplied to the surface portion of the metal material, and the surface portion is rotated by bringing a rod-shaped rotary tool into contact with the surface portion. This is a method for producing a metal material in which the additive material is mixed in to increase the hardness.

  According to this configuration, fine particles having a minimum primary particle size of less than 0.5 μm are supplied to the surface portion of the metal material as an additive, and the rod-shaped rotary tool is brought into contact with the surface portion to which the particles are supplied. Since the friction stir processing (FSP) that rotates while rotating is performed, the additive can be more uniformly mixed in the metal material. Moreover, the crystal grain of a metal material is refined | miniaturized by the dynamic recrystallization in a friction stirring process. For this reason, the hardness of a metal material can be raised further.

  The “minimum portion... Particle diameter” of the particles in the present invention means the minimum diameter when the diameter of the particles is measured at an arbitrary site. For example, in the case of a carbon nanotube having an outer diameter of 25 nm and a length of 250 nm, the particle diameter is 25 nm. Further, the “primary particle size” of the particles in the present invention means the diameter of each particle (primary particle), and “the primary particle size is less than 0.5 μm” means that the primary particle size is 0. It may be less than 5 μm, and includes particles whose primary particle size is 0.5 μm or more, such as secondary particles in which primary particles are aggregated by mutual cohesive force.

  In this case, it is preferable that the additive contains carbon in order to increase the hardness of the metal material.

  Further, it is more preferable that the additive contains fullerene in order to increase the hardness of the metal material.

In addition, it is more preferable that the particles contain C ₆₀ in order to increase the hardness of the metal material.

  On the other hand, another aspect of the present invention is a metal material whose hardness has been increased by the method for producing a metal material of the present invention. According to this configuration, the metal material is mixed with an additive material composed of fine particles having a primary particle size of less than 0.5 μm at the minimum portion in the surface portion by friction stir processing, and the additive material is contained in the metal material. Since the metal particles are uniformly mixed and the crystal grains of the metal material are refined by the friction stir processing, the hardness can be further increased.

  According to the method for producing a metal material of the present invention, the hardness of the metal material can be further increased. In addition, the metal material of the present invention can be made to have a further increased strength.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  Hereinafter, the manufacturing method of a metal material is demonstrated. FIG. 1 is a perspective view showing an embodiment of a method for producing a metal material according to the present invention. As shown in FIGS. 1A and 1B, in the method for manufacturing a metal material according to the present embodiment, the additive 14 supplied to the surface portion of the metal material 10 is made into a metal by a friction stirring process using a rotary tool 16. It mixes in the material 10. As the metal material 10, for example, an Al material, an Fe material, or an Mg material can be applied.

In this embodiment, first, as shown in FIG. 1A, the groove 12 is formed in the surface portion of the metal material 10, and the additive material 14 is filled in the groove. The additive 14 is a particle having a primary particle size of a minimum portion of less than 0.5 μm. More specifically, as the additive 14, silicon carbide or metal carbide such as graphite powder or SiC powder containing carbon having a minimum primary particle size of less than 0.5 μm can be applied. More preferably, carbon nanotubes (sometimes referred to as carbon fibers or carbon fibers) can be applied as the additive 14, and the carbon nanotubes are single-layered cylinders having carbon atoms with an outer diameter of 2 nm or less. A single-walled carbon nanotube (SWCNT), a double-walled carbon nanotube (DWCNT) that is a double-layered cylinder made of carbon atoms, and an outer diameter of 20 to 25 nm and a length of 250 nm or less One or more selected from the group consisting of multiwalled carbon nanotubes (MWCNTs) in which a plurality of cylinders made of carbon atoms are nested in multiple layers can be applied. More preferably, the additive 14 is one or more fullerenes (carbons) selected from the group consisting of C ₆₀ , C ₇₀ , C ₇₆ , C ₇₈ , C ₈₂ and C _{84 in} which the carbon atoms are spherical. Most preferably, as the additive 14, C ₆₀ having a soccer ball-like sphere shape with a carbon atom diameter of 0.7 nm or less is applied as the additive 14. be able to.

Next, a rotating tool 16 as shown in FIG. The rotary tool 16 has a substantially cylindrical shape, and includes a substantially cylindrical probe 18 having a smaller diameter than the main body at the tip. Note that a probe is not necessarily required, and in some cases, a substantially cylindrical rotating tool having no probe may be used. The material of the rotary tool 16 is made of, for example, tool steel such as SKD61 steel standardized by JIS, cemented carbide made of tungsten carbide (WC) or cobalt (Co), or ceramics such as Si ₃ N _4. Can be. As shown in FIG. 1 (b), the probe 18 of the rotary tool 16 is rotated on the groove 12 filled with the additive 14 of the metal material 10, and further rotated along the longitudinal direction of the groove 12. By moving 16, the additive 14 filled in the groove 12 can be stirred by the rotary tool 16, and the additive 14 can be mixed into the metal material 10. In order to sufficiently mix the additive, the rotary tool 16 can be reciprocated while rotating on the groove 12 filled with the additive 14. Alternatively, the additive material 14 can be mixed into the metal material 10 by continuing to rotate the same at the same place without moving the rotary tool 16. In this case, a wide region on the metal material 10 can be strengthened by mixing the additive material 14 at a plurality of continuous locations.

  Hereinafter, the effect of the manufacturing method of the metal material of this embodiment is demonstrated. In the present embodiment, the additive material 14 made of particles having a primary particle size of less than 0.5 μm is supplied to the surface portion of the metal material 10, and the additive material 14 is mixed into the metal material 10 by friction stir processing. . For this reason, even when a material that is difficult to disperse uniformly in the metal material 10 such as carbon nanotubes is used as the additive material 14, the additive material 14 can be uniformly mixed in the metal material 10. Furthermore, the crystal grains of the metal material 10 are refined by dynamic recrystallization in the friction stir processing. For this reason, the strength of the metal material 10 can be further improved.

  In addition, the manufacturing method of the metal material of this invention is not limited to above-described embodiment, Of course, a various change can be added in the range which does not deviate from the summary of this invention. For example, as a method of supplying the additive material 14 to the surface portion of the metal material 10, in addition to the method shown in FIG. A method of jetting the additive 14 to the surface of the metal material 10 from the jet holes provided in the metal plate 10 can be used. Further, the additive 14 is contained in the material constituting the rotary tool 16, and the rotary tool 16 is rotated while being in contact with the metal material 10, whereby the additive is added to the metal material 10 while the rotary tool 16 is worn. Can be supplied. In this method, the additive 14 can be more uniformly supplied to the metal material 10. Alternatively, the additive material can be supplied to the metal material 10 by applying an adhesive tape containing the additive material 14 to the metal material 10 and rotating the adhesive tool 16 while abutting the rotating tool 16 on the adhesive tape. . In this method, the additive 14 can be more easily supplied to the portion on the metal material 10 to be strengthened.

Furthermore, in the method for producing a metal material of the present invention, after two metal materials are abutted or overlapped at the joint, an additive is supplied to the joint, and a rotary tool is inserted into the joint. The hardness of the metal material around the joint can also be increased by performing friction stir welding (FSW).

  Next, an experimental result in which the inventor actually raised the hardness of the metal material by the method for producing the metal material of the present invention will be described.

Experimental example 1
An AZ31 material (Mg alloy containing 3% Al and 1% Zn) having a thickness of 6 mm was prepared. A groove 12 having a width of 1 mm and a depth of 2 mm as shown in FIG. 1A was formed on the surface of the prepared AZ31 material. The formed grooves 12 were filled with C ₆₀ (22) having carbon balls 24 having a diameter of 0.7 nm or less as shown in FIG. As shown in FIG. 3, the C ₆₀ aggregate 26 has a diameter of about 10 to 50 μm. After filling with C ₆₀ , as shown in FIG. 1B, the friction stir processing was performed by the rotary tool 16 having the probe 18 having a diameter of 4 mm and a length of 1.8 mm and made of SKD ₆₁ having a diameter of 12 mm. The rotating speed of the rotating tool was 1500 rpm, and the moving speed of the rotating tool was 50 mm / min.

Figure 4 is a longitudinal sectional view showing a state of a portion subjected to friction stir processing of the present experimental example, FIG. 5 is a diagram showing a state of a portion including a C _60. 4 and 5, it can be seen that C ₆₀ that appears white in the metal material 10 is mixed in the portion A near the surface of the metal material 10 and the portion B deep from the surface stirred by the rotary tool 16. On the other hand, it can be seen from FIG. 4 that C ₆₀ is not mixed in the metal material 10 in the portion C deeper than the boundary 28 from the surface of the metal material 10.

Figure 6 is a diagram showing the crystal grains of the site without the C ₆₀ of this Example, Figure 7 is a diagram showing a crystal grain of a portion including a C _60, FIG. 8 does not include a site containing the C ₆₀ It is a figure which shows the boundary with a site | part. As shown in FIGS. 6 and 8, the crystal grain size of the metal material 10 in the portion C where C ₆₀ is not mixed is as large as 20 μm or more, whereas as shown in FIGS. 7 and 8, C ₆₀ is mixed. It can be seen that the crystal grain size in the portion B is reduced to 500 nm or less.

  FIG. 9 is a table showing the composition of each measurement point in FIG. 4, and each numerical value represents atomic%. As shown in FIG. 9, it can be seen that the carbon content in the part C is not significantly different from that of the AZ31 base material, whereas the carbons are contained in the parts A and B in a large amount.

The a C ₆₀ AZ31 material subjected to friction stir processing is mixed, it was performed and AZ31 material friction stir process is performed without mixing the C _60, a hardness test for AZ31 base material not subjected to friction stir processing . As shown in FIG. 10, the AZ31 material subjected to the friction stirring process with C ₆₀ mixed therein has a small measurement mark 30, whereas the AZ31 material subjected to the friction stirring process without mixing C ₆₀ as illustrated in FIG. 11. It can be seen that the material has a large measurement mark 30. Furthermore, as shown in FIG. 12, the micro hardness of the AZ31 base material not subjected to the friction stir processing is 40 to 50 Hv, and the micro hardness of the AZ31 material subjected to the friction stir processing without mixing C ₆₀ is 50 to 50 In contrast to ₆₀ Hv, the microhardness of the region (nanocomposite layer) where C _{60 of} the AZ31 material mixed with C ₆₀ and subjected to friction stir processing is 128 Hv is greatly improved. I understand.

In the same manner as described above, a friction stir treatment was performed using graphite powder and SiC powder having a particle size of less than 0.5 μm as additive 14. Figure 13 is a diagram showing the crystal grains of AZ31 material containing _{C 60} in this experimental example, FIG. 14 is a diagram showing the crystal grains of AZ31 material containing graphite powder, 15 crystals of AZ31 material containing SiC It is a figure which shows a grain. FIG. 16 is a diagram showing crystal grains of the AZ31 material not subjected to the friction stir processing, and FIG. 17 is a diagram showing crystal grains of the AZ31 material subjected to the friction stir processing. As shown in FIG. 16, the crystal grain size of the AZ31 material not subjected to the friction stir processing is as large as 79.1 μm on average, and the micro hardness is as low as 46 Hv. As shown in FIG. 17, when the friction stir processing is performed, the crystal grain size is refined to 12.9 μm on average, but the micro hardness is improved only to 59 Hv. On the other hand, as shown in FIG. 14, when the graphite powder is mixed and the friction stirring process is performed, the crystal grain size is refined to an average of 2.5 μm, and the microhardness is improved to 64 Hv. Further, as shown in FIG. 15, when the friction stir processing is performed with SiC mixed, the crystal grain size is refined to an average of 6.0 μm, and the micro hardness is improved to 74 Hv. However, as shown in FIG. 13, it can be seen that when the friction stir processing is performed with C ₆₀ mixed, the crystal grain size is most refined and the micro hardness is greatly improved to 128 Hv.

Experimental example 2
An AZ31 material (Mg alloy containing 3% Al and 1% Zn) having a thickness of 6 mm was prepared. A groove 12 having a width of 1 mm and a depth of 2 mm as shown in FIG. 1A was formed on the surface of the prepared AZ31 material. A multi-walled carbon nanotube 32 in which a plurality of cylinders made of carbon atoms having an outer diameter of 20 to 25 nm and a length of 250 nm or less as shown in FIG. As filled. After filling the multi-walled carbon nanotubes 32, as shown in FIG. 1 (b), the friction stir processing is performed by the rotary tool 16 having the probe 18 having a diameter of 4 mm and a length of 1.8 mm and comprising the SKD 61 having a diameter of 12 mm. It was. The rotating speed of the rotating tool was 1500 rpm, and the moving speed of the rotating tool 16 was 100 mm / mm, 50 mm / min, and 25 mm / min.

  FIGS. 19 to 21 are longitudinal sectional views of portions subjected to the friction stir processing at the moving speeds of 100 mm / min, 50 mm / min, and 25 mm / min of the rotary tool 16 in this experimental example, respectively. As shown in FIG. 19, when the moving speed of the rotary tool 16 is 100 mm / min, a portion where the multi-walled carbon nanotubes 32 are aggregated remains black in the drawing, but as shown in FIGS. It can be seen that when the moving speed is 50 mm / min and 25 mm / min, the multi-walled carbon nanotubes 32 are almost uniformly dispersed.

  22, 24 and 26 are plan views of portions subjected to the friction stir processing at the moving speeds of 100 mm / min, 50 mm / min and 25 mm / min of the rotary tool 16 in this experimental example, respectively. It is an enlarged view in each broken line part. As shown in FIGS. 22 to 27, it can be seen that the multi-walled carbon nanotubes that appear white in the drawing are uniformly dispersed as the moving speed of the rotary tool 16 decreases from 100 mm / min to 25 mm / min.

  A hardness test was performed on the AZ31 material mixed with the multi-walled carbon nanotubes and subjected to the friction stirring treatment and the AZ31 base material not subjected to the friction stirring treatment. As shown in FIG. 28, the fine hardness of the AZ31 base material not subjected to the friction stir processing is 41 Hv, whereas as shown in FIG. 29, the minute hardness of the AZ31 material subjected to the friction stir processing by mixing multi-walled carbon nanotubes. It can be seen that the hardness is improved to 78 Hv.

  FIG. 30 is a diagram showing crystal grains of the AZ31 material, FIG. 31 is a diagram showing crystal grains of the AZ31 material that has been subjected to the friction stirring process without mixing multi-walled carbon nanotubes, and FIG. It is a figure which shows the crystal grain of AZ31 material which mixed the carbon nanotube and performed the friction stirring process, and FIG. 33 is an enlarged view of the broken-line part of FIG. As shown in FIGS. 30 and 31, the crystal grains are not made very fine just by applying the friction stirring process, but as shown in FIGS. It can be seen that the crystal grains can be made extremely fine.

Experimental example 3
A5083 material (Al alloy containing about 4.5% Mg) was prepared. A groove 12 having a width of 1 mm and a depth of 2 mm as shown in FIG. 1A was formed on the surface of the prepared A5083 material. The formed groove 12 was filled with powder of a mixture of C ₆₀ and C ₇₀ (hereinafter referred to as MF (Mixed Fullerene)) as an additive 14. After filling with MF, as shown in FIG. 1 (b), a friction stir processing was performed with a rotary tool 16 having a probe 18 having a diameter of 4 mm and a length of 1.8 mm and made of SKD 61 having a diameter of 12 mm. The moving speed of the rotating tool 16 was 50 mm / min, and the rotating speed was 500 rpm, 1000 rpm, 1500 rpm, and 2000 rpm.

  Similarly, after forming the groove 12 in the A5083 material, in order to fill the formed groove 12 with higher density of MF, the MF paste made of paste of MF powder with starch as a binder is filled as the additive 14 did. After filling with the MF paste, a friction stirring process was performed in the same manner. The moving speed of the rotating tool 16 was 50 mm / min, and the rotating speed was 1500 rpm.

  Furthermore, C1020 material (pure copper) was prepared. Similarly, after forming the groove 12 in the C1020 material, the formed groove 12 was filled with MF powder as the additive 14. After filling with MF, a friction stirring process was performed in the same manner. The moving speed of the rotating tool 16 was 50 mm / min, and the rotating speed was 1500 rpm. Further, the friction stir processing was similarly performed on the C1020 material in which the groove formed in the same manner was filled with the MF paste as the additive 14.

  34 to 37 are longitudinal cross-sectional views of portions subjected to the friction stirring process at the rotation speeds of 500 rpm, 1000 rpm, 1500 rpm, and 2000 rpm of the rotary tool 16 in this experimental example, respectively. In the figure, AS indicates the advancing side of the rotary tool 16, and RS indicates the retreating side of the rotary tool 16. MF is dispersed in a region that looks black in FIGS. 34 to 37, it can be seen that the MF is relatively uniformly dispersed as the rotational speed of the rotary tool 16 increases.

  FIG. 38 is a longitudinal cross-sectional view of a portion where the friction stir processing of the A5083 material is performed using MF paste. From FIG. 38, it can be seen that when the friction stir processing is performed using the MF paste, there are densely dispersed regions of MF that appear black in the drawing. FIG. 39 is an enlarged view of FIG. 38 and is a TEM (Transmission Electron Microscope) photograph showing the crystal grains of the A5083 material. In the figure, MF is shown as MF34. From FIG. 39, it can be seen that the crystal grains of the A5083 material, which is the base material, are miniaturized to the nm order.

  FIG. 40 is a graph showing the results of the hardness test of the A5083 material containing MF in Experimental Example 3, and shows the hardness distribution in the depth direction from the surface of the sample in which MF is dispersed in the A5083 material. FIG. 40 shows that when MF is dispersed in the A5083 material, the hardness is remarkably increased as compared with the A5083 base material not containing MF. FIG. 41 is a diagram showing a state of a hardness test of an A5083 base material not containing MF in Experimental Example 3, and FIG. 42 is a diagram of a hardness test of an A5083 material subjected to friction stirring using the MF paste in Experimental Example 3. It is a figure which shows a mode. As shown in FIG. 41, the A5083 material subjected to the friction stir processing without mixing MF has a large measurement mark 30, whereas the A5083 material subjected to the friction stirring processing mixed with MF as shown in FIG. It can be seen that the measurement mark 30 is small.

  FIG. 43 is a longitudinal sectional view of a portion where the friction stir processing of the C1020 material was performed in Experimental Example 3, and FIG. 44 is a longitudinal sectional view of a portion where the friction stir processing of the C1020 material was performed using MF paste in Experimental Example 3. It is. As shown in FIGS. 43 and 44, black regions in which MFs are dispersed can be confirmed.

  FIG. 45 is a graph showing the maximum micro hardness of the sample obtained in the hardness test in Experimental Example 3. In the figure, MF-P / A1050 and MF-P / A5083 indicate samples obtained by subjecting the A1050 material and the A5083 material to friction stirring treatment using MF paste, respectively. In the figure, MF / C1020 indicates a sample obtained by subjecting the C1020 material to a friction stirring process using MF powder. As shown in FIG. 45, it can be seen that the hardness of any sample of A1050 material, A5083 material, and C1020 material increases when MF is dispersed.

It is a perspective view which shows one Embodiment of the manufacturing method of the metal material which concerns on this invention. It is a diagram showing a molecular structure of C ₆₀ to be applied in Experimental Example 1. It is a diagram illustrating a collection of C ₆₀ to be applied to the experimental example 1. It is a longitudinal cross-sectional view which shows the state of the site | part which performed the friction stirring process of Experimental example 1. FIG. It is a diagram showing a state of a portion including a C ₆₀ Experimental Example 1. Is a diagram showing the crystal grains of sites that do not contain C ₆₀ of Experimental Example 1. It is a diagram showing the crystal grains of the site containing the C ₆₀ of Experimental Example 1. Is a diagram showing the boundary between the portion that does not contain a site containing the C ₆₀ of Experimental Example 1. It is a table | surface which shows the composition of each measurement point in FIG. It is a diagram showing a state of hardness tests of AZ31 material containing _{C 60} in Experimental Example 1. It is a diagram showing a state of hardness tests of AZ31 material not containing C ₆₀ in Experimental Example 1. It is a graph which shows the result of the hardness test in Experimental example 1. It is a diagram showing the crystal grains of AZ31 material containing _{C 60} in Experimental Example 1. It is a figure which shows the crystal grain of AZ31 material containing the graphite powder in Experimental example 1. FIG. It is a figure which shows the crystal grain of AZ31 material containing SiC in Experimental example 1. FIG. It is a figure which shows the crystal grain of the AZ31 material in Experimental example 1. FIG. It is a figure which shows the crystal grain of the AZ31 material which performed the friction stirring process in Experimental example 1. FIG. It is a figure which shows the carbon nanotube applied in Experimental example 2. FIG. It is a longitudinal cross-sectional view of the site | part which performed the friction stirring process with the moving speed of 100 mm / min of the rotation tool in Experimental example 2. FIG. It is a longitudinal cross-sectional view of the site | part which performed the friction stirring process with the moving speed of 50 mm / min of the rotary tool in Experimental example 2. FIG. It is a longitudinal cross-sectional view of the site | part which performed the friction stirring process with the moving speed of 25 mm / min of the rotation tool in Experimental example 2. FIG. FIG. 9 is a plan view of a portion subjected to a friction stirring process at a moving speed of a rotating tool of 100 mm / min in Experimental Example 2. It is an enlarged view of FIG. It is a top view of the site | part which performed the friction stirring process with the moving speed of 50 mm / min of the rotation tool in Experimental example 2. FIG. It is an enlarged view of FIG. It is a top view of the site | part which performed the friction stirring process with the moving speed of 25 mm / min of the rotation tool in Experimental example 2. FIG. It is an enlarged view of FIG. It is a figure which shows the mode of the hardness test of AZ31 material which is not performing the friction stirring process in Experimental example 2. FIG. It is a figure which shows the mode of the hardness test of AZ31 material containing the multilayer carbon nanotube in Experimental example 2. FIG. It is a figure which shows the crystal grain of the AZ31 material in Experimental example 2. FIG. It is a figure which shows the crystal grain of the AZ31 material which performed the friction stirring process in Experimental example 2. FIG. It is a figure which shows the crystal grain of AZ31 material containing the multi-walled carbon nanotube in Experimental example 2. FIG. It is an enlarged view of FIG. In Experimental example 3, it is a longitudinal cross-sectional view of the site | part which performed the friction stirring process of A5083 material at the rotational speed of 500 rpm of the rotation tool. In Experimental example 3, it is a longitudinal cross-sectional view of the site | part which performed the friction stirring process of A5083 material with the rotational speed of 1000 rpm of the rotary tool. In Experimental example 3, it is a longitudinal cross-sectional view of the site | part which performed the friction stirring process of A5083 material with the rotational speed of 1500 rpm of a rotary tool. In Experimental example 3, it is a longitudinal cross-sectional view of the site | part which performed the friction stirring process of A5083 material with the rotational speed of 2000 rpm of the rotary tool. It is a longitudinal cross-sectional view of the site | part which performed the friction stirring process of A5083 material using the MF paste in Experimental example 3. FIG. It is an enlarged view of FIG. It is a graph which shows the result of the hardness test of A5083 material containing MF in Experimental example 3. It is a figure which shows the mode of the hardness test of A5083 base material which does not contain MF in Experimental example 3. FIG. It is a figure which shows the mode of the hardness test of A5083 material which performs a friction stirring process using the MF paste in Experimental example 3, and contains MF. It is a longitudinal cross-sectional view of the site | part which performed the friction stirring process of C1020 material in Experimental example 3. FIG. It is a longitudinal cross-sectional view of the site | part which performed the friction stirring process of C1020 material using the MF paste in Experimental example 3. FIG. It is a graph which shows the maximum micro hardness of the sample obtained by the hardness test in Experimental example 3.

Explanation of symbols

10 ... metal member, 12 ... groove, 14 ... additional material, 16 ... rotary tool, 18 ... probe, 20 ... stirring unit, 22 _{... C} 60, 24 ... carbon atoms, a collection of 26 ... _{C 60,} 28 ... boundary, 30 ... measurement mark, 32 ... carbon nanotube, 34 ... MF.

Claims (3)

Supply the fullerene or carbon nanotube additive , which is a particle having a primary particle size of less than 0.5 μm in the smallest part, to the surface part of the metal material, and rotate while bringing a rod-shaped rotary tool into contact with the surface part It is allowed to, the surface sites by mixing particles of the additive material Ru increase the hardness, a manufacturing method of the metal material. The additional material comprises a C _60, method for producing a metal material according to claim 1. Metallic material which increases the hardness by the manufacturing method for a metal material according to claim 1 or 2.