JP5482658B2 - Precursor for foam metal and method for producing foam metal, and precursor for foam metal and foam metal produced by the production method - Google Patents

Description

  The present invention relates to a precursor for a foam metal and a method for producing a foam metal, and a precursor for a foam metal and a foam metal produced by the production method, and in particular, a low-cost precursor for a foam metal having stable quality. Manufacturing method of foam metal precursor, which is an energy-saving process that can be easily manufactured by, manufacturing method of foam metal using precursor for foam metal manufactured by the manufacturing method, and for foam metal manufactured by these manufacturing methods It relates to precursors and foam metals.

  Foam metal made by foaming various metals and alloys such as pure aluminum, pure titanium, aluminum alloy, magnesium alloy, titanium-aluminum alloy, titanium alloy, nickel-aluminum alloy, pure iron, pure copper, steel material, copper alloy It is lightweight, has high specific strength and corrosion resistance, is easy to recycle, and has shock absorption and sound insulation.

  The main applications of foam metal are considered to be automobiles, aerospace, railway vehicles, medical fields, building materials, industrial machine parts, and the like.

  One method of producing foam metal is a precursor method in which a foaming agent is mixed into a base material such as an aluminum alloy to form a precursor, and this precursor is heated and foamed (Banhart, J., Manufacture, characterization and Application of cellular metals and metal foams. Progress in Materials Science, 2001. 46 (6): p559-632).

  In the precursor method, a precursor is prepared by a powder method (Baumgartner, F., I. Duarte, and J. Banhart, Industrialization of powder compact foaming process. Advanced Engineering Materials, 2000. 2 (4): Pp168-174 German Patent Application Publication No. 1048360, German Patent Application Publication No. 4103630 and Roll Joining (Kitazono, K., E. Sato, and K. Kuribayashi, Novel manufacturing process of closed-cell aluminum foam by Scripta Materialia, 2004. 59 (4): pp495-498, Japanese Patent No. 3895292).

  In the powder method, the base material powder and the foaming agent powder are mixed until uniform, and the obtained mixed powder is subjected to operations such as hot extrusion and hot rolling to solidify the mixed powder, and the precursor. It is a method.

  In the rolling joining method, a plurality of base plate materials are prepared, surface treatment is applied to the plate materials as necessary, a foaming agent is sandwiched between the plate materials, and rolling is performed at a predetermined reduction rate, for example, 50%. Then, these plate materials are joined. And the said rolling process is repeated and a foaming agent is disperse | distributed uniformly in a base material, and it is set as a precursor.

  However, in the powder method, the price of the base material powder is higher than that of a generally distributed plate material or the like, and when the base material is an aluminum alloy powder, an oxide film exists on the surface of the powder. Energy is difficult because it is difficult to produce a sufficiently dense precursor, the productivity is low due to the preparation and solidification of the mixed powder, and a large amount of energy is required to solidify the mixed powder. There are problems such as large consumption, and when the mixed powder is prepared, the powder of the base material and the foaming agent tends to be scattered all around, and the working environment may be deteriorated.

  On the other hand, the rolling joining method has the advantage that inexpensive plate materials can be used and existing rolling equipment can be used, but in order to join the plate materials by rolling, pretreatment such as annealing and surface treatment of the joint surface is required. Heat treatment is required before and after rolling, energy consumption is large, rolling must be repeated many times to uniformly disperse the foaming agent, and rolling material must be cut each time rolling is repeated There are many factors that hinder productivity improvement.

  The present invention has been made in view of the above problems, and is a method for producing a precursor for foam metal that is an energy-saving process that can easily produce a precursor for foam metal having stable quality at low cost. It aims at providing the manufacturing method of the foam metal using the manufactured precursor for foam metal, and the precursor for foam metal and the foam metal manufactured by these manufacturing methods.

  According to a first aspect of the present invention, there is provided a step of placing and overlapping a foaming agent between one base material and another base material, and one of the superposed one base material and the other base material. Performing a friction stir processing (FSP) on the surface to join the one base material and the other base material, and simultaneously dispersing the foaming agent into the one base material and the other base material. The present invention relates to a method for producing a precursor for foam metal.

  In the manufacturing method, one base material and another base material are overlapped with a foaming agent sandwiched therebetween, and a substantially cylindrical tool having a protrusion on the tip is placed on one side of the axis. FSP that presses the end portion on the side where the projection of the tool is provided is performed while rotating around. Then, the frictional heat generated by the FSP softens the one and other base materials to cause plastic flow, and the base materials are integrated with each other, and at the same time, the foaming agent is dispersed in the base material to obtain a precursor. .

  The second aspect of the present invention includes a step of placing a foaming agent on the surface of the base material, and a step of dispersing the foaming agent placed on the surface of the base material inside the base material by friction stir processing (FSP). And a method for producing a precursor for a metal foam.

  In the manufacturing method, a foaming agent is placed on the surface of the base material, and the substantially cylindrical tool having a protrusion at the tip is rotated around the axis on the lower surface of the foaming agent in the base material. While performing the FSP, the end of the tool provided with the protrusion is pressed. Then, the base material is softened by the frictional heat generated by the FSP to cause plastic flow, and the foaming agent is dispersed in the base material to obtain a precursor.

  According to a third aspect of the present invention, in the method for producing a precursor for a foam metal according to the first aspect, after performing FSP on one surface of the superposed one base material and the other base material, The present invention relates to an FSP that performs FSP on the other surface of the superposed one base material and the other base material.

  In the manufacturing method, by performing FSP on one surface, the base materials are integrated with each other, and at the same time, the foaming agent is dispersed in the base material. Then, by performing FSP on one surface and then performing FSP on the other surface, the integration of the base materials and the dispersion of the foaming agent into the base material further progress.

  According to a fourth aspect of the present invention, in the method for producing a precursor for a foam metal according to the second aspect, after performing FSP on the surface of the base material on which the foaming agent is placed, the opposite of the base material It relates to what performs FSP on the side surface.

  In the manufacturing method, after FSP is performed on one surface and then FSP is performed on the other surface, the dispersion of the foaming agent into the base material further proceeds.

  According to a fifth aspect of the present invention, in the method for producing a foam metal precursor according to any one of the first to fourth aspects, the base material is pure aluminum or an aluminum alloy.

  In the manufacturing method, by using pure aluminum or an aluminum alloy as a base material, a precursor having pure aluminum or an aluminum alloy as a base material can be obtained.

  A sixth aspect of the present invention relates to the method for producing a precursor for a metal foam according to the fifth aspect, wherein the foaming agent is titanium hydride.

  According to the said manufacturing method, the precursor which uses pure aluminum or aluminum alloy as a base material, and a foaming agent is a titanium hydride is obtained.

  According to a seventh aspect of the present invention, the foam metal precursor produced by the production method according to any one of the first to sixth aspects is heated to a temperature in the vicinity of the melting point of the one and the other base materials. It is related with the manufacturing method of the foam metal which foams.

  In the manufacturing method, by heating the precursor in which the foaming agent is dispersed in the base material to the vicinity of the melting point, the base material is softened and at the same time, the foaming agent is decomposed. It becomes.

  An eighth aspect of the present invention relates to a foam metal precursor produced by the production method according to any one of the first to sixth aspects.

  In the eighth aspect, as described in the description of the first aspect, the frictional heat generated by the FSP softens the one and the other base materials to cause plastic flow, and the base materials are joined together. At the same time, the foaming agent is dispersed in the base material to obtain a precursor.

  A ninth aspect of the present invention relates to a foam metal manufactured by the manufacturing method according to the eighth aspect.

  The foam metal is foamed by heating the foam metal precursor produced by the production method according to any one of the first to sixth aspects to a temperature near the melting point of the one and other base materials. Is a foam metal produced by

  In the manufacturing method according to the first aspect, as described above, the frictional heat generated by the FSP softens the one and the other base materials to cause plastic flow, and at the same time integrates them with the base materials. Since the foaming agent is dispersed in the base material and used as a precursor, according to the first aspect, compared with the conventional powder method and rolling method, a precursor for foam metal having stable quality can be produced at low cost. Easy to manufacture, energy saving, and since the foaming agent is sandwiched between one base material and the other base material, the foaming agent will not scatter and the work environment will not deteriorate A method for producing a precursor for a foam metal is provided.

  In the manufacturing method according to the second aspect, as described above, the base material is softened by the frictional heat generated by the FSP to cause plastic flow, and the foaming agent is dispersed in the base material to form a precursor. According to the second aspect, compared with the conventional powder method and rolling method, a precursor for a foam metal that can be easily produced at low cost and has a stable quality, and is also energy saving. A manufacturing method is provided.

  According to the third aspect, compared with the manufacturing method according to the first aspect, a precursor for a foam metal is obtained in which one and another base material are further integrated and the foaming agent is further uniformly dispersed. A method for producing a foam metal precursor is provided.

  According to the fourth aspect, compared with the manufacturing method according to the second aspect, a precursor for a foam metal is obtained in which one and another base material are further integrated and the foaming agent is more uniformly dispersed. A method for producing a foam metal precursor is provided.

  According to the 5th aspect, the manufacturing method of the precursor for metal foams which can manufacture the precursor which makes a pure aluminum or aluminum alloy a base material with stable quality and also with less energy consumption is provided.

  According to the sixth aspect, there is provided a method for producing a precursor for a foam metal, which can be produced with a stable quality and a lower energy consumption by using a precursor having pure aluminum or an aluminum alloy as a base material and titanium hydride as a foaming agent. Is provided.

  According to the seventh aspect, since the foamed metal is produced by heating and foaming the precursor produced by the production method according to the first aspect, the production of the foamed metal with which a highly uniform foamed metal is obtained. A method is provided.

  According to the 8th aspect, compared with the precursor manufactured with the conventional powder method and the rolling method, quality is more stable, and the precursor for metal foams cheaper is provided.

  According to the 9th aspect, compared with the foam metal manufactured from the precursor manufactured by the conventional powder method and the rolling method, quality is more stable and cheap metal foam is provided.

FIG. 1 is a perspective view showing a method for laminating a foaming agent between two base materials in the method for producing a precursor for foam metal according to the present invention. FIG. 2 is a perspective view showing a laminate formed by laminating a foaming agent between two base materials in the method for producing a precursor for foam metal according to the present invention. FIG. 3 is a perspective view showing an example in which grooves or recesses for accommodating a foaming agent are formed in the base material used in the method for producing a precursor for a foam metal according to the present invention. FIG. 4 is a perspective view showing a place where FSP is started for the laminate shown in FIG. FIG. 5 is a side view showing that FSP is performed on the laminate shown in FIG. FIG. 6 is a perspective view showing a place where FSP is performed on the laminate shown in FIG. 2. FIG. 7 is a schematic cross-sectional view showing a state of a stirring unit formed by performing FSP on a laminate. FIG. 8 is a perspective view showing a base material used in the method for producing a precursor for foam metal according to the present invention in which a concave portion for accommodating a foaming agent is formed on the upper surface. FIG. 9 is a perspective view showing a state where the foaming agent is filled in the recessed portion of the base material shown in FIG. FIG. 10 is a perspective view showing a place where FSP is started for the laminate shown in FIG. FIG. 11 is a perspective view showing a place where the first FSP is performed in the laminated body shown in FIG. 9.

1. Embodiment 1
Hereinafter, an example of the manufacturing method of the precursor for foam metal of this invention is demonstrated using drawing.

  First, as shown in FIG. 1, the foaming agent 3 is sandwiched between the plate-like base material 1 and the plate-like base material 2, and the base material 1 and the base material 2 are overlapped as shown in FIG. Together, a laminate 7 is obtained. In the example shown in FIG. 1, the base material 2 is thicker than the base material 1, but the base material 1 and the base material 2 may have the same thickness, and the base material 1 is more preferable than the base material 2. It may be thick.

  Further, in the example shown in FIG. 1, the base material 2 disposed on the lower side is not provided with a groove or recess for accommodating the foaming agent 3, but is disposed on the lower side as shown in FIG. 3. A groove 2a or a recessed portion 2b for accommodating the foaming agent 3 may be provided in the base material 2 to be formed.

  Next, as shown in FIGS. 4 and 5, the friction stir tool 4 provided with the protrusion 4a at the tip of the columnar body 4b is rotated at a predetermined rotational speed as indicated by an arrow b, and is indicated by an arrow a. In this way, it is pressed against one end of one surface of the laminate 7 and moved toward the other end of the laminate 7 as indicated by an arrow c. In FIG. 5, the solid line indicates a state in which the tip of the friction stir tool 4 is in contact with the laminated body 7, and the alternate long and two short dashes line indicates a state in which the laminated body 7 is pressed and the protrusion 4 a is inserted. FIG. 6 shows the friction stir tool 4 moved to the other end of the laminate 7.

  The height of the protrusion 4a is preferably larger than the thickness of one base material. In this case, in a state in which the friction stir tool 4 is pressed against the laminate 7 and the protrusion 4a is penetrated, the protrusion 4a penetrates the base material 1 into the base material 2 as shown by a two-dot chain line in FIG. To reach.

  Further, if the spiral is formed in the protrusion 4a or a groove in the longitudinal direction or the circumferential direction is formed, the stirring action can be enhanced.

  Furthermore, when scanning the friction stir tool 4, a forward angle may be given along the scanning direction, or scanning may be performed while being held perpendicular to the operation direction.

  By pressing the laminate 7 while rotating the friction stir tool 4 about the axis, friction heat is generated between the laminate 7 and the friction stir tool 4, and the stirring unit 6 is formed. In the stirring unit 6, the base material 1, the foaming agent 3, and the base material 2 are uniformly mixed as shown in FIG. Then, when the friction stir tool 4 moves toward the other end of the laminated body 7, the stirring portion 6 is formed toward the other end of the laminated body 7 as shown in FIG. In this way, the precursor 10 is formed. 7 shows a cross section of the laminate 7 shown in FIG. 6 cut along a plane XX orthogonal to the surfaces of the base material 1 and the base material 2. FIG.

  When the diameter of the friction stir tool 4 is smaller than the width of the laminated body 7, in other words, the width of the base material 1 and the base material 2, and the stirrer 6 is formed only in a small part of the laminated body 7, The stirrer 4 is moved back and forth between one end and the other end of the laminate 7 by shifting the position of pressing the laminate 7 or the position pressed against the laminate 7 is shifted from one end to the other end of the laminate 7. What is necessary is just to repeat the operation to move toward a predetermined number of times.

  Finally, the precursor 10 thus formed is heated to a predetermined temperature to decompose the foaming agent 3 and foam the stirring portion 6 in the precursor 10, thereby forming a foam metal.

  As the base material 1 and the base material 2, aluminum and its alloy, magnesium and its alloy, titanium and its alloy, specifically, pure aluminum, pure titanium, aluminum alloy, magnesium alloy, A titanium-aluminum alloy, a titanium alloy, or a nickel-aluminum alloy is used. On the other hand, nickel and its alloys, precious metals, zinc and their alloys, lead and their alloys, tin and their alloys, etc. are used in applications such as catalysts, adsorbents, sound absorbing materials, and vibration-proof materials. It is not limited to or alloys.

  The foaming agent 3 is not particularly limited as long as it does not adversely affect the base material 1 and the base material 2, and specifically, inorganic foams such as titanium hydride, zirconium hydride, and calcium carbonate. Agents, azo compounds, organic foaming agents such as hydrazine derivatives are used.

  The shape of the protrusion 4a is not particularly limited as long as the friction stir tool 4 is in a form in which a protrusion is formed at the center of the distal end surface of the cylindrical main body 4b. Specific examples of the shape of the protrusion 4a include a cylinder, a cone that decreases toward the tip, and a truncated cone that decreases toward the tip. The depth at which the friction stir tool 4 is pressed against the base material 1 or 2 is preferably such that the protrusion 4 a is substantially buried in the base material 1 or 2.

  The temperature at which the precursor 10 is foamed is preferably near the melting point of the base material 1 and the base material 2.

  The rotational speed of the friction stir tool 4 is preferably about 500 rpm to 3000 rpm, but this range is not particularly limited.

  The example in which the FSP is performed from the surface on the base material 1 side in the laminate 7 has been described above. However, in the laminate 7, after the FSP is performed from the surface, the FSP is performed from the surface on the base material 2 side. May be.

2. Embodiment 2
Hereinafter, another example of the method for producing a precursor for a foam metal according to the present invention will be described with reference to the drawings.

  As shown in FIG. 8, a plate-like member is prepared as a plate-like base material 2 in which a recessed portion 2 b for accommodating the foaming agent 3 is formed in the central portion.

  Next, as shown in FIG. 9, the recess 2 b of the base material 2 is filled with the foaming agent 3, and as shown in FIG. 10, while the friction stir tool 4 is rotated at a predetermined rotational speed as indicated by an arrow b. Then, one end of the portion of the base material 2 filled with the foaming agent 3 is pressed as indicated by an arrow a, and moved toward the other end of the portion of the base material 2 as indicated by an arrow c. The friction stir tool 4 is as described in the first embodiment. However, the height of the protrusion 4a is preferably larger than the depth of the recessed portion 2b and smaller than the thickness of the portion of the base material 2 where the recessed portion 2b is formed. FIG. 11 shows the friction stir tool 4 moved to the other end of the base material 2.

  Thereby, a stirring part as shown in FIG. 7 is formed.

  The example in which FSP is performed from the surface of the base material 2 on which the foaming agent 3 is placed has been described above. However, even after performing FSP from the surface, the FSP may be performed from the surface opposite to the surface. Good.

  As base materials 1 and 2, an A5083 aluminum alloy having a width of 70 mm and a length of 200 mm was used. The base material 1 had a thickness of 3 mm, and the base material 2 had a thickness of 6 mm. Titanium hydride (TiH2, particle size <45 μm) was used as the blowing agent 3.

  As shown in FIG. 1, the foaming agent 3 was sprayed along the length direction of the base material 2 on the center of the upper surface of the base material 2. The spraying amount was set to be approximately 1% by mass of the stirring unit 6 formed by FSP. After the foaming agent 3 was sprayed on the base material 2, the base material 1 was placed on the upper surface of the base material 2 to obtain a laminate 7.

  Next, as shown in FIGS. 4 and 5, FSP was performed on the laminate 7 in the atmosphere. An FSW device manufactured by Hitachi Engineering Co., Ltd. was used for the FSP. Further, as the friction stirring tool 4, a main body 4b made of SKH51 high-speed tool steel having a diameter of 17 mm, a protrusion 4a having a cylindrical shape, a diameter of 6 mm, and a height of the protrusion 4a of 4.8 mm was used. The rotational speed of the friction stir tool 4 was set to 1400 rpm, the moving speed was set to 100 mm / min, and the advance angle was set to 3 degrees.

  When the setting of the friction stir tool 4 was completed, the friction stir tool 4 was scanned immediately above the portion of the base material 2 where the foaming agent 3 was sprayed. Next, scanning is performed while shifting toward one side edge in the length direction of the stacked body 7 by the diameter of the protrusion 4a, and finally on one side edge in the length direction of the stacked body 7 by the diameter of the protrusion 4a. A total of three passes were scanned by shifting the scanning direction. As a result, a precursor 10 having a stirring portion 6 having a width about three times the diameter of the protrusion 4a along the length direction was formed at the central portion of the laminate 7.

  Finally, a cube having a side of 6 mm was cut out from the stirring unit 6 of the precursor 10 and charged into an electric furnace, heated to 973 K at a heating rate of 0.5 K / s, and held at that temperature for 10 minutes. The cube was removed from the electric furnace and air-cooled. When the cube after foaming was cut, it was found that bubbles were generated inside.

DESCRIPTION OF SYMBOLS 1 Base material 2b Recessed part 2a Groove 2 Base material 3 Foaming agent 4a Protrusion 4b Main body 4 Friction stirring tool 6 Stirring part 7 Laminated body 10 Precursor

Claims (18)

Placing a foaming agent between one base material and another base material and superposing them;
Friction stir processing (FSP) is performed on one surface of the superposed one base material and the other base material to join the one base material and the other base material, and at the same time, the foaming agent is added to the one base material. A process of dispersing the base material and other base materials;
The manufacturing method of the precursor for metal foams containing. Placing a foaming agent on the surface of the base material;
Dispersing the foaming agent placed on the surface of the base material inside the base material by friction stir processing (FSP);
The manufacturing method of the precursor for metal foams containing.   The FSP is performed on the other surface of the superimposed one base material and the other base material after performing the FSP on one surface of the superposed one base material and the other base material. The manufacturing method of the precursor for metal foams as described in 2 ..   The manufacturing method of the precursor for metal foams of Claim 2 which performs FSP to the surface on the opposite side of the said base material after performing FSP to the surface by which the foaming agent of the said base material was mounted.   The method for producing a precursor for a foam metal according to claim 1, wherein the base material is titanium, iron, pure aluminum, or an aluminum alloy.   The method for producing a precursor for foam metal according to claim 2, wherein the base material is pure aluminum or an aluminum alloy.   The method for producing a precursor for foam metal according to claim 3, wherein the base material is pure aluminum or an aluminum alloy.   The method for producing a precursor for foam metal according to claim 4, wherein the base material is pure aluminum or an aluminum alloy.   The method for producing a precursor for a foam metal according to claim 5, wherein the foaming agent is titanium hydride.   The method for producing a precursor for a foam metal according to claim 6, wherein the foaming agent is titanium hydride.   The method for producing a precursor for a foam metal according to claim 7, wherein the foaming agent is titanium hydride.   The method for producing a precursor for a foam metal according to claim 8, wherein the foaming agent is titanium hydride.   A method for producing a foam metal, wherein the foam metal precursor produced by the production method according to claim 1 is heated to a temperature in the vicinity of the melting point of the one and other base materials to foam the inside.   A method for producing a foam metal, wherein the foam metal precursor produced by the production method according to claim 2 is heated to a temperature in the vicinity of the melting point of the one and other base materials to foam the inside.   The manufacturing method of the foam metal which heats the precursor for metal foams manufactured with the manufacturing method of Claim 11 to the temperature of the melting | fusing point of the said one and another base material, and foams an inside.   A method for producing a foam metal, wherein the foam metal precursor produced by the production method according to claim 12 is heated to a temperature in the vicinity of the melting point of the one and other base materials to foam the inside.   The precursor for metal foams manufactured with the manufacturing method of Claim 1.   The precursor for metal foams manufactured with the manufacturing method of Claim 2.

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