METAL COMPOSITE COMPRISING ALIGNED PRECIPITATE AND PREPARATION METHOD THEREFOR
The present invention provides a metal composite with an oriented precipitate, in which a solid solution is created by performing solution treatment or homogenization on an alloy, a discontinuous cellular precipitate or lamellar precipitate of 40% or more per unit area of 500 μm×500 μm is forcibly created by aging and oriented by plastic working. The present invention provides a method of manufacturing a metal composite with an oriented precipitate which includes: a material preparing step of preparing a molded alloy; a solid solution creating step of creating a solid solution by performing heat treatment on the alloy in a single phase area; a precipitate forcible-creating step of creating a cellular precipitate or a lamellar precipitate of 40% or more per unit area of 500 μm×500 μm by aging the alloy containing the solid solution; and a precipitate orienting step of orienting the precipitate by performing plastic working on the alloy containing the precipitate.
The present invention relates to a metal composite with an oriented precipitate and a method of manufacturing the same, and more particularly, to a metal composite with an oriented precipitate that has improved strength and electric conductivity by forcibly creating a precipitate through aging after creating a solid solution, which is created by selectively adding precipitation-promoting metal to an alloy and performing solution treatment or homogenization, and by orienting the forcibly created precipitate through plastic working, and a method of manufacturing the metal composite.
BACKGROUND ARTDue to high electric conductivity, copper is widely used in electric/electronic circuits, but as information communication parts have become highly integrated and reduced in weight, copper is exposed to high current and voltage when it is used in electric/electronic circuits.
Furthermore, when it is used as a conductive material, it is further exposed to a severe environment, so high strength and electric conductivity and excellent thermal stability are required.
That is, copper alloys are used for connectors, accumulators, or connectors for connecting a controller to various electric parts, actuators, and sensors in vehicles equipped with increased electric devices and it is strongly required to downsize these connectors.
In particular, connectors disposed close to an engine are exposed to the heat and vibration of the engine, and when a large amount of current is applied to the connectors, the connectors generate heat and increase the temperature to a high level. Accordingly, those connectors require high reliability under such environments.
Accordingly, as a material of copper alloy connectors used in common vehicles, a Cu—Fe—P alloy (Korean Patent No. 10-0997560) or a Cu—Mg—P alloy (Korean Patent No. 10-0417756) have been disclosed. The strength of the former alloy is improved by precipitating a Fe—P compound based on the addition of both of Fe and P.
Furthermore, there have been proposed an alloy of which mobility resistance is improved by adding Zn (Japanese Patent Application Publication No. 168830) and an alloy of which mitigation of stress resistance is improved by adding Mg (Japanese Patent Application Publication No. 358033).
The latter alloy is improved in tensile strength, electric conductivity, and mitigation of stress resistance by improving strength and creeping characteristic by adding Mg and P.
As described above, copper alloys can improve its electric conductivity, thermal stability, and strength by adding various components.
However, various components that are added to copper alloys make electric conductivity and strength opposite to each other.
That is, when the strength is increased, the electric conductivity is decreased, and when the electric conductivity is increased, a microstructure changes and strength decreases.
SUMMARY OF INVENTION Technical ProblemAn object of the present invention is to provide a metal composite with an oriented precipitate that has improved strength and electric conductivity by forcibly creating a precipitate through aging after creating a solid solution, which is created by selectively adding precipitation-promoting metal to an alloy and performing solution treatment or homogenization, and by orienting the forcibly created precipitate through plastic working, and a method of manufacturing the metal composite.
Solution to ProblemIn order to achieve the object, the present invention provides a metal composite with an oriented precipitate, in which a solid solution is created by performing solution treatment or homogenization on an alloy, a discontinuous cellular precipitate or lamellar precipitate of 40% or more per unit area of 500 μm×500 μm is forcibly created by aging, and the forcibly created precipitate is oriented by plastic working.
The present invention provides a metal composite with an oriented precipitate, in which a solid solution is created by performing solution treatment or homogenization on an alloy, a discontinuous cellular precipitate or lamellar precipitate of 40% or more per unit area of 630 μm×480 μm is forcibly created by aging, and the forcibly created precipitate is oriented by plastic working.
The present invention provides a metal composite with an oriented precipitate, in which a solid solution is created by performing solution treatment or homogenization on an alloy, a discontinuous cellular precipitate or lamellar precipitate is forcibly created by aging, and the forcibly created precipitate is oriented by plastic working to have a length of 2.0 μm or more per unit area of 3.5 μm×1.5 μm in a copper base.
The oriented precipitate has a length to diameter aspect ratio of 100 or more.
The alloy that became the solid solution is rapidly cooled by water quenching or cooled by air.
The aging is performed for three hours or more.
Precipitation-promoting metal is added in the solution treatment or homogenization process.
The precipitation-promoting metal includes any one of titanium (Ti) and vanadium (V).
The present invention provides a method of manufacturing a metal composite with an oriented precipitate which includes: a material preparing step of preparing a molded alloy; a solid solution creating step of creating a solid solution by performing heat treatment on the alloy in a single phase area; a precipitate forcible-creating step of creating a cellular precipitate or a lamellar precipitate of 40% or more per unit area of 500 μm×500 μm by aging the alloy containing the solid solution; and a precipitate orienting step of orienting the precipitate by performing plastic working on the alloy containing the precipitate.
The present invention provides a method of manufacturing a metal composite with an oriented precipitate which includes: a material preparing step of preparing a molded alloy; a solid solution creating step of creating a solid solution by performing heat treatment on the alloy in a single phase area; a precipitate forcible-creating step of creating a cellular precipitate or a lamellar precipitate of 40% or more per unit area of 630 μm×480 μm by aging the alloy containing the solid solution; and a precipitate orienting step of orienting the precipitate by performing plastic working on the alloy containing the precipitate.
The present invention provides a method of manufacturing a metal composite with an oriented precipitate which includes: a material preparing step of preparing a molded alloy; a solid solution creating step of creating a solid solution by performing heat treatment on the alloy in a single phase area; a precipitate forcible-creating step of creating a cellular precipitate or a lamellar precipitate of 40% or more per unit area of 630 μm×480 μm by aging the alloy containing the solid solution; and a precipitate orienting step of orienting the precipitate to have a length of 2.0 μm or more per unit area of 3.5 μm×1.5 μm in a copper base by performing plastic working on the alloy containing the precipitate.
In the material preparing step, precipitation-promoting metal including any one of titanium (Ti) and vanadium (V) is added.
The solid solution creating step is a process of performing heating within a temperature range of above the lowermost temperature where a single phase is maintained in the state diagram and below the melting temperature−7.5×X (X is wt % of an added component other than copper base) of a copper base phase for two hours or more.
The precipitate forcible-creating step is performed at a temperature below 47×X (X is wt % of an added component other than copper base)+melting temperature of a copper base phase×0.4(K, absolute temperature).
The alloy is a copper alloy and (Ni+Si), which is X, is 4.8 to 7.5wt %.
Advantageous Effects of InventionThe present invention relates to a metal composite with an oriented precipitate that can function as a reinforcing material of a composite by artificially orienting an artificially created precipitate through plastic working.
Accordingly, electric conductivity and strength are improved.
Furthermore, it is possible to adjust the amount of precipitate by selectively adding precipitation-promoting metal.
A metal composite 20 with a discontinuous cellular precipitate or a lamellar precipitate according to the present invention is described hereafter with reference to
The terms and words used in the present specification and claims should not be interpreted as being limited to typical meanings or dictionary definitions, but should be interpreted as having meanings and concepts relevant to the technical scope of the present invention based on the rule according to which an inventor can appropriately define the concept of the term to describe most appropriately the best method he or she knows for carrying out the invention.
Therefore, the configurations described in the embodiments and drawings of the present invention are merely the most preferable embodiments and do not represent all of the technical spirit of the present invention. Thus, the present invention should be construed as including all the changes, equivalents, and substitutions included in the spirit and scope of the present invention at the time of filing this application.
The present invention provides a metal composite 20 that has improved strength and electric conductivity by providing a composite type strengthening effect by creating and artificially orienting a precipitate of a cellular or lamellar structure that reduces mechanical strength in metal.
That is, the metal composite 20 of the present invention was achieved by artificially creating a precipitate in an alloy 10, as in
The precipitate may be a discontinuous cellular precipitate or a continuous lamellar precipitate and, for the plastic working, various processes such as drawing, rolling, and extruding may be selected.
As shown in the figure, precipitation-promoting metal 10 for increasing the amount of a precipitation may be added to the alloy in the process of manufacturing the metal composite 20.
The precipitation-promoting metal is titanium (Ti) or vanadium (V) and a copper alloy was selected in a preferred embodiment of the present invention.
Since the precipitation-promoting metal is selectively added, electric conductivity or strength can be artificially adjusted.
The length to diameter aspect ratio of a precipitate, artificially created by aging for more than three hours before plastic working, is 100 or more and a discontinuous precipitate area of 40% or more of the entire area of the alloy 10 is formed, so as to improve strength and electric conductivity.
According to the present invention, it is possible to forcibly create a discontinuous cellular precipitate or lamellar precipitate of 40% or more per unit area of 500 μm×500 μm through aging after creating a solid solution by performing solution treatment or homogenization on the alloy 10 and it is also possible to create a discontinuous cellular precipitate or a continuous lamellar precipitate of 40% or more per unit area of 630 μm×480 μm.
Furthermore, it is possible to orient the forcibly created precipitate to have a length of 2.0 μm or more per unit area of 3.5 μm×1.5 μm in a copper base through plastic working.
A method of manufacturing the metal composite 20 is described hereafter with reference to
As shown in the figure, the method of manufacturing the metal composite 20 of the present invention includes a material preparing step (S100) of preparing a molded alloy 10, a solid solution creating step (S200) of creating a solid solution by thermally treating the alloy 10 in a one phase area, a precipitate forcible-creating step (S300) of creating a cellular precipitate or a lamellar precipitate by aging the alloy 10 containing the solid solution, and a precipitate orienting step (S400) of orienting the precipitate by performing plastic working on the alloy 10 containing the precipitate.
The material preparing step (S100) is a process of preparing an alloy (see
In detail, the alloy 10, which is a copper alloy containing Ni—Si in an embodiment of the present invention, is a mold formed by any one of rolling, drawing, and extruding and contains a residual precipitate.
The precipitation-promoting metal includes any one of titanium (Ti) and vanadium (V).
The weight percent (wt %) of (Ni+Si), which is the sum of nickel (Ni) and silicon (Si), is limited to 81% or more of the highest solid solubility to the entire weight of the alloy 10, that is, 4.8 to 7.5wt % and the balance is copper (Cu) and other unavoidable impurities.
The precipitation-promoting metal is selectively included, and titanium (Ti) of 0.025 to 0.24wt % or vanadium (V) of 0.028 to 0.086wt % may be included.
After the material preparing step (S100), the solid solution creating step (S200) is performed. The solid solution creating step (S200) is a process for removing a residual precipitation, and when precipitation-promoting metal is included in the material preparing step (S100), the solution solubility may be low.
The solid solution creating step (S200) is a process of heating the alloy 10 and the precipitation-promoting metal at a predetermined temperature or more and the preferred temperature in the solid solution creating step (S200) is preferably 950° C. or more for the copper-based alloy and under 1084 (melting point of pure copper)−7.5×X.
X is the weight percent (wt %) of (Ni+Si) described above, 1084−7.5×X where a liquid state is not produced and 950° C. or more that is the highest solid solution limit temperature where a solid solution can be produced are preferable for the Cu—Ni—Si, Cu—Ni—Si—Ti, Cu—Ni—Si—V alloy 10 that is an embodiment of the present invention.
That is, referring to
After the solid solution creating step (S200), the discontinuous precipitate forcible-creating step (S300) is performed.
The precipitate forcible-creating step (S300) is a process of creating a discontinuous cellular precipitate or a discontinuous lamellar precipitate in the alloy 10, and in an embodiment of the present invention, when water quenching or air cooling is performed and precipitation-promoting metal was added after the solid solution creating step (S200), aging was performed for two or more hours, and when precipitation-promoting metal was not added, aging was performed for five or more hours, thereby forcibly creating a discontinuous precipitate.
That is,
Accordingly, it can be seen that a precipitate having a normal shape was created in the comparative example, but a discontinuous precipitate was created in the embodiment.
As in these figures, a precipitate was not oriented in the comparative example in which slow cooling was performed in a furnace, but in the embodiment in which rapid cooling was performed in the solid solution creating step (S200), it can be seen that the precipitate was oriented in the processing direction in the precipitate orienting step (S400).
Accordingly, it is preferable to perform rapid cooling using water quenching or air cooling in the solid solution creating step (S200).
After the solid solution creating step (S200), the precipitate forcible-creating step (S300) is performed. The precipitate forcible-creating step (S300) is a step for increasing the amount of a precipitate formed in the alloy 10 in the solid solution creating step (S200), and aging was performed in an embodiment of the present invention.
Microstructures before/after the precipitate forcible-creating step (S300) are comparatively described with reference to
First, as in
The contents of components in the comparative example and the embodiments were as in the following Table 1.
As in
When heating was performed at 400° C. in the precipitate forcible-creating step (S300), as in
On the other hand, in the comparative example, a precipitate was not created even though heating was performed at 500° C. for seven hours, as in
The microstructure did not show a large change in the comparative example before the precipitate forcible-creating step (S300), as in
In the comparative example, when vanadium (V) or titanium (Ti) not added, a small amount of discontinuous precipitate was formed even though the precipitate forcible-creating step (S300) was performed for a long time, the result being opposite to the preferred embodiment.
That is, the figures provide graphs for analyzing the amount of creation of a precipitate when X, which is weight percent (wt %) of (Ni+Si), was changed, in which it can be seen that when X, which is the weight percent (wt %) of (Ni+Si), is included over 4.81wt % to the entire weight of the alloy 10, a discontinuous precipitate or a lamellar precipitate occupied an area of 40% or more.
However, when X, which is the weight percent (wt %) of (Ni+Si), is less than 4.81wt %, a discontinuous precipitate having an area of 40% or more was not created.
Accordingly, it is preferable that X, which is the weight percent (wt %) of (Ni+Si), is in the range of 4.8 to 7.5wt % in the state diagram shown in
Based on the embodiment described above, as the result of performing the precipitate forcible-creating step (S300) at 500° C., as in
Based on the test result described above, the temperature (° C.) for the discontinuous forcible creating step (S300) is 47×X+260° C(533K) or less and has this relationship.
Furthermore, the temperature (° C.) for the solid solution creating step (S200) is 1084−7.5×X and 950° C. or more, which is the highest soluble limit where a solid solution can be created and has this relationship.
The discontinuous precipitate is created from 0.4×the melting point (K, absolute temperature) of copper-based metal or more where dispersion starts, so a discontinuous precipitate is forcibly created in the area in the state diagram shown in
The precipitate orienting step (S400) is performed after the discontinuous precipitate forcible-creating step (S300). The precipitate orienting step (S400) is a process for artificially orienting a discontinuous precipitate or a discontinuous lamellar precipitate formed inside in accordance with the embodiment described above.
That is, in an embodiment of the present invention, rolling, drawing, or extruding was employed in the precipitate orienting step (S400),
Microstructures of a comparative example and an embodiment are compared hereafter with reference to
In the comparative example shown in
The difference in whether there is orientation of microstructures considerably depends on mechanical properties, as in
First, referring to
However, it can be seen that the increases in strength are very different in the comparative example and the embodiment employing drawing in the precipitate orienting step (S400).
That is, the strength was 600 MPa before drawing, but it slightly increased to 800 MPa after drawing in the comparative example, but in the embodiment, the strength was about 500 MPa before drawing, but it increased close to 1100 MPa after drawing. Accordingly, it can be seen that the strength of the alloy 10 is higher in the embodiment than the comparative example after the precipitate orienting step (S400).
Accordingly, it can be seen that a precipitate can function as a reinforcing material by forcibly creating a precipitate through the precipitate forcible-creating step (S300) and then forcibly orienting the precipitate.
As in the figure, the comparative example and the embodiment show the same strength of 200 MPa in the state of the alloy 10, but the strength of the comparative example increased to 430 MPa, which is higher than the strength of the embodiment, after the solid solution creating step (S200) and the precipitate forcible-creating step (S300).
However, after the precipitate forcible-creating step (S400), the strength increased by 190 MPa in the comparative example, the strength in the embodiment increased by 480 MPa, which shows an effect of increasing strength of 290 MPa in comparison to the comparative example.
That is, since discontinuous precipitates are arranged in parallel in the metal composite 20 manufactured in accordance with a preferred embodiment of the present invention, it can be seen that the mechanical properties were considerably increased in comparison to the mechanical properties of the metal composite 20 manufactured in accordance with a common manufacturing method.
The scope of the present invention is not limited to the embodiments described above and many other modifications based on the present invention may be achieved by those skilled in the art within the scope of the present invention.
For example, titanium was used as precipitation-promoting metal in an embodiment of the present invention, but vanadium may also be used.
INDUSTRIAL APPLICABILITYThe present invention relates to a metal composite with an oriented precipitate functioning as a reinforcing material for a composite by artificially orienting a precipitate, which is artificially created, through plastic working, and a method of manufacturing the metal composite, so electric conductivity and strength are improved. Furthermore, if necessary, it is possible to artificially adjust the amount of precipitate by selectively adding precipitation-promoting metal, so it can be used in various fields by adjusting electrical and mechanical properties.
Claims
1. A metal composite with an oriented precipitate, wherein a solid solution is created by performing solution treatment or homogenization on an alloy, a discontinuous cellular precipitate or lamellar precipitate of 40% or more per unit area of 500 μm×500 μm is forcibly created by aging, and the forcibly created precipitate is oriented by plastic working.
2. A metal composite with an oriented precipitate, wherein a solid solution is created by performing solution treatment or homogenization on an alloy, a discontinuous cellular precipitate or lamellar precipitate of 40% or more per unit area of 630 μm×480 μm is forcibly created by aging, and the forcibly created precipitate is oriented by plastic working.
3. A metal composite with an oriented precipitate, wherein a solid solution is created by performing solution treatment or homogenization on an alloy, a discontinuous cellular precipitate or lamellar precipitate is forcibly created by aging, and the forcibly created precipitate is oriented by plastic working to have a length of 2.01 μm or more per unit area of 3.5 μm×1.5 μm in a copper base.
4. The metal composite of claim 1, wherein the oriented precipitate has a length to diameter aspect ratio of 100 or more.
5. The metal composite of claim 4, wherein the alloy that became the solid solution is rapidly cooled by water quenching or cooled by air.
6. The metal composite of claim 5, wherein the aging is performed for three hours or more.
7. The metal composite of claim 6, wherein precipitation-promoting metal is added in the solution treatment or homogenization process.
8. The metal composite of claim 7, wherein the precipitation-promoting metal includes any one of titanium (Ti) or vanadium (V).
9. A method of manufacturing a metal composite with an oriented precipitate, the method comprising:
- a material preparing step of preparing a molded alloy;/a solid solution creating step of creating a solid solution by performing heat treatment on the alloy in a single phase area;
- a precipitate forcible-creating step of creating a cellular precipitate or a lamellar precipitate of 40% or more per unit area of 500 μm×500 μm by aging the alloy containing the solid solution; and
- a precipitate orienting step of orienting the precipitate by performing plastic working on the alloy containing the precipitate.
10. A method of manufacturing a metal composite with an oriented precipitate, the method comprising:
- a material preparing step of preparing a molded alloy;
- a solid solution creating step of creating a solid solution by performing heat treatment on the alloy in a single phase area;
- a precipitate forcible-creating step of creating a cellular precipitate or a lamellar precipitate of 40% or more per unit area of 630 μm×480 μm by aging the alloy containing the solid solution; and
- a precipitate orienting step of orienting the precipitate by performing plastic working on the alloy containing the precipitate.
11. A method of manufacturing a metal composite with an oriented precipitate, the method comprising:
- a material preparing step of preparing a molded alloy;
- a solid solution creating step of creating a solid solution by performing heat treatment on the alloy in a single phase area;
- a precipitate forcible-creating step of creating a cellular precipitate or a lamellar precipitate by aging the alloy containing the solid solution; and
- a precipitate orienting step of orienting the precipitate to have a length of 2.0 μm or more per unit area of 3.5 μm×1.5 μm in a copper base by performing plastic working on the alloy containing the precipitate.
12. The method of any one of claim 9 wherein precipitation-promoting metal including any one of titanium (Ti) and vanadium (V) is added in the material preparing step.
13. The method of claim 12, wherein the solid solution creating step is a process of performing heating within a temperature range of above the lowermost temperature where a single phase is maintained in the state diagram and below the melting temperature−7.5×X (X is wt % of an added component other than copper base) of a copper base phase for two hours or more.
14. The method of claim 12, wherein the solid solution creating step is a process of performing heating within a temperature range of above the lowermost temperature where a single phase is maintained in the state diagram and below the melting temperature−7.5 ×X (X is wt % of an added component other than copper base) of a copper base phase for two hours or more.
15. The method of claim 14, wherein the alloy is a copper alloy and (Ni+Si), which is X, is 4.8 to 7.5 wt %.
16. The metal composite of claim 2, wherein the oriented precipitate has a length to diameter aspect ratio of 100 or more.
17. The metal composite of claim 3, wherein the oriented precipitate has a length to diameter aspect ratio of 100 or more.
18. The method of claim 10 wherein precipitation-promoting metal including any one of titanium (Ti) and vanadium (V) is added in the material preparing step.
Type: Application
Filed: Feb 14, 2013
Publication Date: Dec 10, 2015
Inventor: Seung Zeon HAN (Changwon-si, Gyeongsangnam-do)
Application Number: 14/762,772
