Production method of bonding body, bonding body, and heat sink

Abstract

To provide a bonding body with a good bonding quality.SOLUTION: A production method of the bonding body comprises a bonding step of contacting a sintered body directly with an object and obtaining the bonding body through heat treatment. The sintered body contains an alloy.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing a bonded body, a bonded body, and a heat sink. [Background technology]

[0002] Conventionally, various methods have been used to join members containing metal, such as brazing, friction stir welding, laser welding, diffusion welding, etc. For example, Patent Document 1 discloses a method for manufacturing a joined body in which rolled sheets of aluminum material are joined together. Summary of the Invention [Problem to be solved by the invention]

[0003] An object of the present invention is to provide a bonded body having good bonding quality. [Means for solving the problem]

[0004] In order to solve the above-mentioned problems, a manufacturing method of a joined body according to one embodiment of the present invention includes a joining step of directly contacting a sintered body with an object and performing a heat treatment to obtain a joined body, the sintered body including an alloy. Effect of the Invention

[0005] According to one aspect of the present invention, a bonded body having good bonding quality can be provided. [Brief description of the drawings]

[0006] [Figure 1] 4 is a flowchart showing a method for manufacturing a bonded body according to the first embodiment of the present invention. [Diagram 2] FIG. 1 is a schematic diagram of a molding system for producing a sintered body used in a manufacturing method of a bonded body according to an embodiment of the present invention. [Diagram 3] FIG. 2 is a schematic diagram of a molding apparatus for producing a precursor used in a method for producing a bonded body according to an embodiment of the present invention. [Figure 4]FIG. 2 is a schematic diagram of a control unit of a molding apparatus that produces a precursor used in a manufacturing method of a bonded body according to one embodiment of the present invention. [Diagram 5] FIG. 2 is a schematic diagram of an optical microscope photograph showing a cross section of a sintered body used in the manufacturing method for a bonded body according to the first embodiment of the present invention. [Figure 6] FIG. 1 is a diagram showing a joint body according to an embodiment of the present invention. [Figure 7] 1 is a schematic diagram of an optical microscope photograph showing a cross section near a bonded boundary of a bonded body according to one embodiment of the present invention. [Figure 8] 1 is a schematic diagram of an optical microscope photograph showing a cross section of an object according to an embodiment of the present invention. [Figure 9] FIG. 13 is a diagram showing a bonded body according to another embodiment of the present invention. [Figure 10] 10 is a flowchart showing a method for manufacturing a bonded body according to a second embodiment of the present invention. [Figure 11] FIG. 1 is a diagram showing a joint body according to an embodiment of the present invention. [Figure 12] FIG. 2 is a schematic diagram of an optical microscope photograph showing a cross section near a bonded boundary of a bonded body obtained by bonding a sintered body and an object according to one embodiment of the present invention. [Figure 13] FIG. 2 is a schematic diagram of an optical microscope photograph showing a cross section near a joint boundary of a joint body obtained by joining sintered bodies according to one embodiment of the present invention. [Figure 14] FIG. 11 is a schematic diagram of an optical microscope photograph showing a cross section near a bonded boundary of a bonded body obtained by bonding sintered bodies according to a second embodiment of the present invention. [Figure 15] 10 is a flowchart showing a method for manufacturing a bonded body according to a third embodiment of the present invention. [Figure 16] 10 is a flowchart showing a method for manufacturing a bonded body according to a fourth embodiment of the present invention. [Figure 17] 13A to 13C are diagrams showing an example of an object used in a manufacturing method for a bonded structure according to a fourth embodiment of the present invention. [Figure 18] 18 is a cross-sectional view showing a bonded body obtained by bonding a sintered body to the object in FIG. 17. [Figure 19]13A and 13B are diagrams showing another example of an object used in the method for manufacturing a bonded body according to the fourth embodiment of the present invention. [Figure 20] FIG. 13 is a diagram showing another example of an object used in the method for manufacturing a bonded body according to the fourth embodiment of the present invention. [Figure 21] 21 is a cross-sectional view showing a bonded body obtained by bonding a sintered body to the object in FIG. 20. [Figure 22] FIG. 11 is a cross-sectional view showing a state before a lid is joined to a container in a joined body according to a fourth embodiment of the present invention. [Figure 23] 23 is a cross-sectional view showing the assembled body of FIG. 22 after a lid has been joined to a container. FIG. [Figure 24] 13 is a flowchart showing a method for manufacturing a bonded body according to a fifth embodiment of the present invention. [Diagram 25] FIG. 13 is a diagram showing a bonded body according to a fifth embodiment of the present invention. [Figure 26] FIG. 2 is an enlarged view of a sintered body according to one embodiment of the present invention. [Figure 27] FIG. 13 is a diagram showing a first modified example of a bonded body according to an embodiment of the present invention. [Figure 28] FIG. 11 is a diagram showing a second modified example of a bonded body according to an embodiment of the present invention. [Figure 29] FIG. 13 is a diagram showing a third modified example of a bonded body according to an embodiment of the present invention. [Diagram 30] FIG. 13 is a schematic diagram of an optical microscope photograph showing a cross section in the vicinity of a bonded boundary of a bonded structure according to still another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings, common parts are denoted by the same or corresponding reference numerals, and the description thereof may be omitted.

[0008] <Method of manufacturing the bonded body> <<First embodiment>> An example of a manufacturing method of a bonded body according to a first embodiment of the present invention and a modeling system and a modeling apparatus used in the manufacturing method of a bonded body according to the present embodiment will be described with reference to FIGS.

[0009] 1 is a flowchart showing a method for manufacturing a bonded body according to the first embodiment of the present invention. The method for manufacturing a bonded body according to the first embodiment of the present invention includes a bonding step. Moreover, the method for manufacturing a bonded body according to the first embodiment of the present invention includes a sintering step prior to the bonding step.

[0010] In the sintering step, a sintered body is obtained. In the sintering step, for example, a precursor is sintered to obtain a sintered body. Here, sintering refers to heating a molded object containing powder or a green compact obtained by compressing and molding powder at a temperature below the melting point of the components that make up the powder, and baking and solidifying it. The sintering step is performed in the sintering step S1 shown in FIG. 1.

[0011] The sintered body is obtained by sintering a precursor. The sintered body includes an alloy. In this specification, the "sintered body" includes an alloy, and preferably has crystal grains with an average diameter of 10 μm or more. Here, the crystal grains are preferably covered with a eutectic portion. Note that the "rolled body" is a rolling process of a metal shaped object formed by sintering, casting, etc., but even if it is a sintered product, the average diameter of the crystal grains becomes small due to the subsequent rolling process, so such a rolled body is not a sintered body.

[0012] The elements contained in the alloy are not particularly limited, and may be a combination of two or more metal elements, or may be a combination of one or more metal elements and one or more nonmetal elements. The metal elements contained in the alloy are, for example, metal elements selected from aluminum (Al), iron (Fe), titanium (Ti), copper (Cu), silver (Ag), gold (Au), magnesium (Mg), calcium (Ca), zinc (Zn), etc. The alloy is preferably an Al alloy. The Al alloy is more preferably an AlSi alloy or an AlSiMg alloy.

[0013] The precursor is a molded body before sintering that will become a sintered body by sintering. The precursor contains a powder. The powder contained in the precursor contains two or more elements, and at least one of the two or more elements is a metal element.

[0014] The precursor may contain either a mixture of powders of single elements or a powder of an alloy. In consideration of the precision of the joined body, it is more preferable that the two or more elements contained in the precursor are elements that constitute an Al alloy.

[0015] The particle size of the powder contained in the precursor is not particularly limited, but is preferably 1 μm to 500 μm, more preferably 3 μm to 200 μm, and further preferably 5 μm to 100 μm. Here, the particle size means the average particle size defined by the median diameter (d50).

[0016] The particle size of the powder contained in the precursor is determined in consideration of the ease of densification in the sintering process as well as the ease of handling when producing the precursor. For example, in the case of an additive manufacturing method, the particle size of the powder is determined based on the ease of forming a powder layer.

[0017] The precursor may be produced by any method, including, for example, an additive manufacturing method, a press molding method, a metal powder injection molding method (MIM: Metal Injection Molding), a casting method, and the like.

[0018] The additive manufacturing method is a method of producing a three-dimensional object (a three-dimensional object or a solid object) by stacking powder layers containing powder using a 3D printer. The object obtained by the additive manufacturing method is called a green body. The green body is an example of a precursor.

[0019] In addition, the press molding method is a method in which a movable die is pressed after powder is filled into the die to obtain a powder compact. Metal powder injection molding (MIM) is a method in which a binder is added to metal powder to make pellets, which are then injected into a die to produce a green body. Slip casting is a method in which a binder is added to metal powder to make a slurry, which is then poured into a die, released, and dried to produce a green body.

[0020] Among these, it is preferable to use an additive manufacturing method as the method for producing the precursor. That is, it is preferable that the precursor is a shaped object produced by an additive manufacturing method. The method for producing a bonded body according to the first embodiment may include a precursor producing step of producing a precursor. For example, the precursor producing step is performed before the sintering step S1 shown in FIG. 1.

[0021] Examples of additive manufacturing methods include fused deposition modeling (FDM) and binder jetting (BJT).

[0022] Fused deposition modeling (FDM) is a method of forming green bodies by extruding a rod made of a mixture of resin and metal from a fine nozzle and layering it.

[0023] The binder jetting method (BJT) is a method for forming green bodies by applying a binder as a forming liquid to a powder layer containing powder, solidifying the powder with the binder, and layering it. In BJT, the solvent component of the binder contained in the obtained green body is dried and degreased.

[0024] As an additive manufacturing method, it is preferable to use a BJT, since it is possible to obtain green bodies with complex shapes that cannot be realized by molding using a mold.

[0025] The heating temperature in the sintering step (hereinafter referred to as the sintering temperature) is not particularly limited. The sintering temperature is, for example, 300°C or more and 2500°C or less, preferably 400°C or more and 2000°C or less, and more preferably 500°C or more and 1000°C or less. By setting the sintering temperature to 300°C or more and 2500°C or less, a sintered body in which the precursor is sufficiently sintered can be obtained.

[0026] The heating time in the sintering step (hereinafter referred to as sintering time) is not particularly limited. For example, the sintering time is 15 minutes or more and 24 hours or less, preferably 30 minutes or more and 18 hours or less, and more preferably 1 hour or more and 12 hours or less. By setting the sintering time to 15 minutes or more and 24 hours or less, a sintered body in which the precursor is sufficiently sintered can be obtained.

[0027] In the sintering process, a sintered body having a specific sintered structure is produced. The sintered body has a eutectic portion containing two or more elements and crystal grains made of one metal element. Here, the eutectic portion refers to a region where solid phases of two types of composition are crystallized. The crystal grains are surrounded by the eutectic portion. Being surrounded by the eutectic portion means that the eutectic portion exists around the crystal grains, and it is not necessary for the eutectic portion to surround the entire periphery of the crystal grains. It is preferable that the eutectic portion exists unevenly within the sintered body.

[0028] The average grain size of the sintered body is 10 μm or more, preferably 50 μm or more, more preferably 90 μm or more, and is 500 μm or less, preferably 400 μm or less, more preferably 200 μm or less.

[0029] Here, a molding system for producing a precursor and sintering the precursor to obtain a sintered body, for example, a case where a BJT is applied, will be described with reference to Fig. 2. Fig. 2 is a schematic diagram of a molding system for producing a sintered body used in a manufacturing method for a bonded body according to one embodiment of the present invention. The molding system 1 includes a molding apparatus 100, a drying apparatus 200, an excess powder removing apparatus 300, and a sintering apparatus 400.

[0030] The molding apparatus 100 molds a molded object. The drying apparatus 200 dries the molded object molded by the molding apparatus 100. The excess powder removing apparatus 300 removes excess powder adhering to the molded object dried by the drying apparatus 200. The sintering apparatus 400 sinters the molded object from which the excess powder has been removed. In the sintering apparatus 400, the molded object may be degreased before sintering. The sintering apparatus 400 carries out the sintering step of the manufacturing method for a bonded body of this embodiment.

[0031] The modeling system 1 may be configured with four devices, namely, the modeling device 100, the drying device 200, the excess powder removing device 300, and the sintering device 400, as separate devices, or may be configured with the four devices integrated into one device, or may be configured with some of the functions being installed in the modeling device 100 or the sintering device 400. Furthermore, at least some of the functions of the drying device 200 or the excess powder removing device 300 may be omitted as appropriate.

[0032] Next, a description will be given of the modeling apparatus 100. Fig. 3 is a schematic diagram of a modeling apparatus that prepares a precursor used in a manufacturing method of a bonded body according to an embodiment of the present invention. Fig. 4 is a schematic diagram of a control unit of the modeling apparatus that prepares a precursor used in a manufacturing method of a bonded body according to an embodiment of the present invention.

[0033] The modeling apparatus 100 includes a modeling unit 10 and an application unit 20. The modeling unit 10 forms a powder layer 111 containing a powder 11. The powder 11 is an example of a powder containing two or more elements contained in a precursor in one embodiment of the present invention. The application unit 20 applies a modeling liquid 21 to the powder layer 111 to form a modeling layer 112. The modeling apparatus 100 stacks a plurality of modeling layers 112 to form a modeled object.

[0034] The modeling apparatus 100 includes a modeling unit 10 and an application unit 20. The modeling unit 10 forms a powder layer 111 containing powder 11. The application unit 20 applies a modeling liquid 21 to the powder layer 111 to form a modeling layer 112. In the modeling apparatus 100, a plurality of modeling layers 112 are stacked to form a modeled object.

[0035] The modeling section 10 includes a powder tank 12 and a lamination unit 13. The powder tank 12 includes a supply tank 121, a modeling tank 122, a supply stage 123, a modeling stage 124, and an excess powder tank 125. The powder tank 12 is box-shaped. The tops of the supply tank 121, the modeling tank 122, and the excess powder tank 125 are open. The lamination unit 13 includes a flat section 131 and a powder removal section 132.

[0036] The supply tank 121 is a tank that supplies the powder 11 to the modeling tank 122. The supply tank 121 holds the powder 11 to be supplied to the modeling tank 122. A supply stage 123 is provided at the bottom of the supply tank 121. The supply stage 123 moves up and down in the vertical direction (Z direction). The side of the supply stage 123 is disposed so as to contact the inner side of the supply tank 121.

[0037] The powder 11 required for modeling is supplied to the modeling tank 122 from the supply tank 121. In the modeling tank 122, a powder layer 111 and a modeling layer 112 are formed. Furthermore, in the modeling tank 122, a plurality of modeling layers 112 are stacked to form a model.

[0038] A supply stage 123 and a modeling stage 124 are provided at the bottom of the supply tank 121 and the modeling tank 122, respectively, and move up and down in the vertical direction (Z direction). The side of the modeling stage 124 is disposed so as to contact the inner side of the modeling tank 122. The upper surfaces of the supply stage 123 and the modeling stage 124 are kept horizontal.

[0039] The surplus powder tank 125 is a tank that holds surplus powder 11 among the powder 11 flattened by the flat portion 131 when forming the powder layer 111. A means for sucking the powder 11 may be provided at the bottom of the surplus powder tank 125, or a means for removing the surplus powder tank 125 may be provided. The surplus powder tank 125 is disposed next to the modeling tank 122. The surplus powder 11 held in the surplus powder tank 125 may be returned to the supply tank 121, or may be returned to the supply tank 121 via a powder supplying device.

[0040] The powder supplying device may be disposed above the supply tank 121, and supplies the powder 11 to the supply tank 121 before modeling begins or when the amount of powder 11 in the supply tank 121 decreases. Note that the powder tank 12 includes two tanks, the supply tank 121 and the modeling tank 122, but it may include only the modeling tank 122, and powder may be supplied to the modeling tank 122 from the powder supplying device.

[0041] Methods for transporting the powder 11 from the powder supplying device to the supply tank 121 include a screw conveyor method using a screw, a pneumatic transport method using air, and the like.

[0042] The flattening unit 131 flattens the modeling layer 112 and the powder layer 111. The flattening unit 131 flattens the modeling layer 112 by rotating a recoater as a rotating body. By rotating the flattening unit 131, the powder 11 on the supply stage 123 of the supply tank 121 is supplied to the modeling tank 122, and the powder layer 111 is formed.

[0043] The flat portion 131 moves back and forth in the Y direction along the stage surface (the surface on which the powder 11 is loaded) of the modeling stage 124. More specifically, the flat portion 131 moves horizontally from the outside of the supply tank 121 to pass above the supply tank 121 and the modeling tank 122.

[0044] As a result, the powder 11 is transferred and supplied onto the modeling tank 122, and the flat portion 131 passes over the modeling tank 122 and flattens the powder 11 to form a powder layer 111. The flat portion 131 is a member that is longer than the inner dimensions of the modeling tank 122 and the supply tank 121. Note that the flat portion 131 may be a blade or a bar that is a plate-like member.

[0045] Powder removal part 132 removes powder adhering to flat part 131. Powder removal part 132 moves together with flat part 131 while in contact with the peripheral surface of flat part 131.

[0046] The application unit 20 includes a carriage 211 and a head 212. The head 212 applies the modeling liquid 21 to the powder layer 111.

[0047] The head 212 is, for example, an inkjet head, and has a nozzle row in which a plurality of nozzles are arranged. A colored object may be formed by dispensing a cyan modeling liquid, a magenta modeling liquid, a yellow modeling liquid, and a black modeling liquid, or a single color modeling liquid may be dispensed from a plurality of nozzles. The method for dispensing the modeling liquid may be an inkjet method or a dispenser method.

[0048] At least one head 212 is mounted on a carriage 211, and moves back and forth in the X (main scanning), Y (sub-scanning), and Z directions by a motor, a guide member, and the like.

[0049] The molding apparatus 100 includes a control unit 30. As shown in Fig. 4, the control unit 30 includes a CPU (Central Processing Unit) 301, a ROM (Read Only Memory) 302 that stores programs for executing control and other fixed data, and a RAM (Random Access Memory) 303 that temporarily stores molding data and the like.

[0050] The modeling data is received from a modeling data creation device 304 such as an external computer. The modeling data creation device 304 creates modeling data by slicing the final model into modeling layers 112. The control unit 30 performs modeling operations for each modeling layer 112. The modeling data creation device 304 may be separate from the modeling device 100 or may be integrated with the modeling device 100. The control unit 30 may be located inside the modeling device 100 or outside the modeling device 100.

[0051] The above is an explanation of the method for producing the precursor and the sintered body when, for example, a BJT is applied. Returning to FIG. 1, the method for producing the bonded body of the first embodiment will be described.

[0052] The joining step joins a sintered body and an object. Joining a sintered body and an object means joining two members to be joined, one of which is a sintered body and the other is an object. In this specification, the members to be joined refer to the members to be joined, and here the sintered body and the object correspond to the members to be joined. The joining step is performed in the joining step S2 shown in FIG. 1.

[0053] The object constitutes one of the members to be joined, separate from the sintered body constituting the other member to be joined, but may be a sintered body obtained in the same manner as the sintered body constituting the one of the members to be joined. The object is, for example, a rolled body, a cast body, a forged body, an extruded body, etc. The rolled body does not include a sintered body, and refers to a body obtained by rolling a cast body obtained by melting powder, etc.

[0054] In the joining step, it is preferable to heat the sintered body in a temperature range where the sintered body generates a liquid phase. It is more preferable that this temperature range is a temperature range where the metal crystals generated in the sintered body (hereinafter referred to as the metal crystal portion) do not generate a liquid phase. If the temperature during joining (hereinafter sometimes referred to as the joining temperature or the joining process temperature) is too high, the metal crystals may become liquid, leading to deformation of the members. If the joining temperature is too low, the eutectic portion may not become liquid sufficiently, resulting in poor joining.

[0055] In addition, a liquid phase is generated from the sintered body by heating the vicinity of the joining surface with the object. In this embodiment, the eutectic portion corresponds to a region generated by crystallizing two types of solid phases after the liquid phase is generated in the sintered body produced by sintering in the sintering process.

[0056] The temperature range in which the liquid phase occurs in the sintered body varies depending on the metal elements contained in the sintered body. For example, in the case of a sintered body containing an aluminum alloy, the temperature range in which the liquid phase occurs in the sintered body is 300°C to 2500°C, preferably 400°C to 2000°C, more preferably 500°C to 1000°C, and even more preferably 550°C to 700°C.

[0057] In the joining step, it is preferable to heat the sintered body containing the alloy in a temperature range where a liquid phase of 5% by mass or more and less than 50% by mass is generated in the sintered body containing the alloy. In particular, in the case of a sintered body containing an aluminum alloy, it is preferable to heat the sintered body containing the aluminum alloy in a temperature range where a liquid phase of 5% by mass or more and less than 35% by mass is generated in the sintered body containing the aluminum alloy, more preferably in a temperature range where a liquid phase of 10% by mass or more and less than 30% by mass is generated, and further preferably in a temperature range where a liquid phase of 15% by mass or more and less than 25% by mass is generated.

[0058] If the liquid phase generated in the sintered body containing the aluminum alloy is less than 5% by mass, the liquid phase may be insufficient, causing poor bonding, while if the liquid phase generated in the sintered body containing the aluminum alloy is more than 35% by mass, the liquid phase may be excessively advanced, causing the sintered body to have difficulty in maintaining its shape.

[0059] When the sintered body contains an aluminum alloy, the crystal grains contained in the bonded body are made of aluminum, and the eutectic portion is made of elements that constitute the aluminum alloy. The crystal grains and the eutectic portion have different metal compositions. For example, when a sintered body containing an alloy of silicon and aluminum is used, the crystal grains contained in the bonded body contain aluminum elements, and the eutectic portion contains aluminum elements and silicon elements.

[0060] In the bonding step, the time required for bonding (hereinafter referred to as bonding time) is arbitrary, but is preferably set to the time required for the liquid phase to be generated from the eutectic portion for 5 minutes or more. By setting the bonding time to 5 minutes or more for the liquid phase to be generated from the eutectic portion, the liquid phase can be sufficiently filled into the boundary surface.

[0061] In the bonding process, the bonding environment is arbitrary. In the bonding process, for example, it is preferable to bond in a vacuum, a rare gas atmosphere such as nitrogen or argon, or a reducing atmosphere such as hydrogen. In the bonding process, the sintered body and the object are bonded and completely cooled, and the manufacturing method of the bonded body according to the first embodiment of the present invention is completed.

[0062] Fig. 5 is a schematic diagram of an optical microscope photograph showing a cross section of a sintered body used in the manufacturing method of a bonded body according to the first embodiment of the present invention. As a cross section of the sintered body according to the first embodiment of the present invention, the bonded portion between the sintered body and the object includes a eutectic portion. By the sintering process, the sintered body containing the alloy is produced with the eutectic portion unevenly distributed at the boundary portion of the metal crystal. In Fig. 5, a part of the eutectic portion is indicated by an arrow.

[0063] Fig. 6 shows a joined body according to one embodiment of the present invention. Fig. 7 is a schematic diagram of an optical microscope photograph showing a cross section near a joining boundary of a joined body according to one embodiment of the present invention (when the object to be joined with the sintered body is a metal or an alloy). In Fig. 7, as in Fig. 5, a part of a eutectic part is indicated by an arrow. Fig. 8 is a schematic diagram of an optical microscope photograph showing a cross section of an object according to one embodiment of the present invention (when the object is a metal or an alloy).

[0064] 6 includes a sintered body 3 and an object 4. In the joining process, the sintered body 3 is placed on the object 4. In addition, the sintered body 3 and the object 4 are joined via a joining part 5.

[0065] The sintered body 3 is obtained by sintering a precursor containing two or more elements. The precursor is, for example, an object produced by a manufacturing method such as BJT or MIM.

[0066] The object 4 may be the same as the sintered body 3, or may be different. If they are the same, for example, the sintered body 3 and the object 4 may be produced by a BJT, the sintered body 3 may be produced by a BJT and the object 4 may be produced by MIM, or the sintered body 3 may be produced by MIM and the object 4 may be produced by a BJT. If they are different, for example, the sintered body 3 may be produced by a BJT, and the object 4 may be a rolled or cast body containing a metal or alloy, a ceramic molded body, or the like.

[0067] Moreover, the object 4 may have the same shape as the sintered compact 3 or a different shape. Furthermore, the object 4 may have the same size as the sintered compact 3 or a different size.

[0068] When the object 4 contains a metal or an alloy, in the joined body 2 formed by joining the sintered body 3 and the object 4, when the sintered body 3 is reheated in the joining step, a eutectic portion (hereinafter referred to as a eutectic portion) contained in the sintered body 3 locally and preferentially becomes liquid. The eutectic portion then diffuses to the object 4 side that is in physical contact with the sintered body 3, thereby promoting joining. In the cross section of the joined body according to this embodiment, the joining portion between the sintered body and the object includes a eutectic portion.

[0069] In Fig. 7, a cross section of the bonded boundary of the bonded body is shown, with the sintered body in the upper part and the object containing metal or alloy in the lower part. In Fig. 7, the eutectic part indicated by the arrow in the lower part of the drawing indicates that the eutectic part is diffusing from the sintered body 3 to the object 4 side.

[0070] At this time, since the metal crystal parts remain in a solid phase within the sintered body, the entire sintered body does not deform, and the joining can be performed while maintaining the shape of the sintered body. Note that the rolled body has eutectic parts finely distributed throughout, as shown in Fig. 8. Therefore, when attempting to join rolled bodies together using this embodiment, the metal crystal parts cannot maintain a solid phase within the rolled body, and there is a risk that the entire rolled body will deform.

[0071] In contrast, the manufacturing method of the bonded body of the first embodiment includes a sintering step and a bonding step, and therefore it is possible to provide a bonded body that retains the shape of the bonded members without using conventional manufacturing methods for bonded bodies.

[0072] Traditional joining methods involve applying a flux to break down the oxide layer on the metal surfaces and allow a liquid phase to permeate the interface.

[0073] On the other hand, in the sintered body used in this embodiment, when the eutectic portion unevenly distributed in the sintered body becomes liquid, the oxide film that exists on the metal surface and is a factor of sintering inhibition is destroyed, so there is no need to apply flux. Therefore, in the manufacturing method of the bonded body of the first embodiment, the process of removing flux after sintering is not required. Also, by not using flux in this way, it is possible to provide a bonded body that does not generate flux residue that causes sintering defects.

[0074] Other conventional joining methods used in the manufacturing of joined bodies include brazing, friction stir welding, laser welding, diffusion bonding, and the like.

[0075] Brazing is a method in which a metal with a lower melting point than the materials being joined is heated to melt it and fill the gaps between the materials being joined.

[0076] Friction stir welding is a method in which the workpieces are overlapped and joined by the frictional heat generated by pressing a rotating tool against the boundary and its periphery.

[0077] Laser welding is a method in which the objects to be welded are overlapped, and a laser is focused and irradiated on the boundary and its surroundings, melting and joining the objects locally. Since the area that can be welded is limited to the area that can be irradiated with the laser light, this method is not suitable for complex shapes. In addition, since the joining area is limited to the points or lines that can be irradiated with the laser, this method is not suitable for joining large surfaces.

[0078] Diffusion bonding is a method in which base materials are brought into close contact with each other, and pressure is applied to the base materials at or below their melting points to the extent that plastic deformation does not occur, and the bonding is achieved by utilizing the diffusion of atoms that occurs between the bonding surfaces.

[0079] However, the conventional joined bodies obtained by these joining methods did not have good joining quality.

[0080] In contrast, the method for producing a bonded body according to the first embodiment includes the above-mentioned sintering step and bonding step, and thus can provide a bonding method with good bonding quality.

[0081] In the manufacturing method of the bonded body of the first embodiment, the sintered body is heated in a temperature range where the liquid phase occurs in the sintered body in the bonding process, so that the bonding temperature is not too high, and deformation of the bonded body due to liquid phase of the metal crystals can be prevented. Also, by heating the sintered body in such a temperature range, the bonding temperature is not too low, so that the liquid phase of the eutectic portion progresses sufficiently, and bonding failure can be prevented.

[0082] As a result, in the manufacturing method of the bonded body of the first embodiment, even when bonding a sintered body and an object, the sintered body and the object can be bonded by directly contacting each other without using a brazing material, etc. Therefore, according to the present embodiment, it is possible to provide a manufacturing method of a bonded body with good bonding quality.

[0083] In the manufacturing method of the bonded body of the first embodiment, since the precursor is a shaped object produced by an additive manufacturing method, it is possible to produce sintered bodies and bonded bodies with complex shapes that cannot be realized by molding.

[0084] Fig. 9 is a diagram showing a bonded body according to another embodiment of the present invention. In Fig. 9, parts common to Fig. 6 are given the same or corresponding reference numerals as those in Fig. 6, and description thereof will be omitted.

[0085] 9 includes a sintered body 3, an object 4, and a joint 5. The sintered body 3 includes a gyroid structure G. That is, the sintered body including the gyroid structure G is joined above the object 4.

[0086] Since the additive manufacturing method is the binder jetting method, it is possible to reliably manufacture sintered bodies and bonded bodies with complex shapes that cannot be realized by molding. Therefore, according to this embodiment, it is possible to provide a bonded body 2 in which a sintered body 3 having a gyroid structure is bonded to an object 4.

[0087] In the manufacturing method of the joined body of the first embodiment, the sintered body contains an aluminum (Al) alloy, and since Al has a low temperature at which the liquid phase of the alloy is generated, the effect of the sintered body on the structure of the objects to be joined can be reduced.

[0088] In the manufacturing method of the bonded body of the first embodiment, by heating in the bonding step in a temperature range where a liquid phase occurs in the sintered body at 5 mass % or more and 50 mass % or less, sufficient liquid phase is generated from the eutectic portion, and bonding failure can be prevented. In addition, since excessive liquid phase generation is suppressed, the shape of the sintered body or bonded body can be maintained. The liquid phase generation rate can be calculated by thermodynamic calculation based on the alloy composition.

[0089] <<Second embodiment>> Fig. 10 is a flow chart showing a method for producing a bonded body according to a second embodiment of the present invention. In the second embodiment, parts common to the first embodiment are denoted by the same or corresponding reference numerals as those in Fig. 1, and description thereof will be omitted.

[0090] The method for manufacturing a bonded body according to the second embodiment further includes a smoothing step. The smoothing step is performed before the bonding step. The smoothing step smoothes at least one of the bonding surfaces of the sintered body and the object. Here, the bonding surface refers to a surface where one of the bonded members and the other of the bonded members contact each other. The smoothing step is performed in a smoothing step S11 shown in FIG. 10.

[0091] The method of the smoothing step is not particularly limited. Examples of the method of the smoothing step include cutting with a tool such as a milling cutter, grinding with a tool such as a grindstone, and polishing such as buff polishing and electrolytic polishing. By smoothing the joining surface in this way, the surface roughness of the treated surface can be reduced before and after the smoothing treatment.

[0092] The surface roughness Ra of the joining surfaces after smoothing is arbitrary, but is preferably 12.5 μm or less, more preferably 8.4 μm or less, and further preferably 6.3 μm or less. If the surface roughness Ra of the joining surfaces is 12.5 μm or less, it is possible to reduce a gap that occurs between the joining surfaces of one joined member and the joining surfaces of the other joined member during joining.

[0093] The surface roughness Ra can be measured using a laser microscope (Keyence Corporation, shape analysis laser microscope VK-X1000). When using a laser microscope, the measurement conditions are: lens magnification 5x, Z direction measurement pitch 12μm, 14 measurement lines (7 horizontal lines with line spacing 0.40mm, 7 vertical lines with line spacing 0.27mm) are drawn in an area of ​​2.74×2.06mm, and the average roughness value is taken as the surface roughness Ra.

[0094] In the method for producing a bonded body according to the second embodiment, by including the smoothing step, better bonding quality can be provided.

[0095] Fig. 11 is a diagram showing a bonded body according to one embodiment of the present invention. Fig. 12 is a schematic diagram of an optical microscope photograph showing a cross section near a bonded boundary of a bonded body obtained by bonding a sintered body and an object according to one embodiment of the present invention. Fig. 13 is a schematic diagram of an optical microscope photograph showing a cross section near a bonded boundary of a bonded body obtained by bonding sintered bodies according to one embodiment of the present invention. Fig. 14 is a schematic diagram of an optical microscope photograph showing a cross section near a bonded boundary of a bonded body obtained by bonding sintered bodies according to a second embodiment of the present invention. In Figs. 12 and 13, parts common to Fig. 11 are given the same or corresponding reference numerals as those in Fig. 11, and description thereof will be omitted.

[0096] Here, cross-sectional views of the bonded body 2 shown in Fig. 11 taken along line AA are shown in Figs. 12 to 14. Note that no smoothing step was carried out in Figs. 12 and 13, but the smoothing step was carried out in Fig. 14.

[0097] For example, as shown in Figure 12, in the joined body 2 in which a sintered body 3 and an object 4 are joined, a joint 5, which is the boundary between the sintered body 3 and the object 4, can be seen. Also in Figure 12, crystal grains C can be seen in the white part, and eutectic E can be seen in the black part. In the joined body 2, eutectic E can be seen not only in the sintered body 3 but also in the object 4. The eutectic E that has melted from the sintered body 3 penetrates into the object 4, joining the sintered body 3 and the object 4.

[0098] Similarly, in the case of joining two sintered bodies, as shown in Fig. 13, the boundary of the joint 5 is visible. In contrast, in the case of joining two sintered bodies shown in Fig. 14 after smoothing, the boundary of the joint 5 is barely visible.

[0099] Furthermore, by carrying out such a smoothing step, the bonded portions 5 of the resulting bonded body can be in close contact with each other, and therefore the bond strength of the bonded portions 5 of the bonded body can be increased.

[0100] <<Third embodiment>> Fig. 15 is a flow chart showing a method for manufacturing a bonded body according to a third embodiment of the present invention. In the third embodiment, parts common to the first and second embodiments are denoted by the same or corresponding reference numerals as those in Fig. 1 and Fig. 10, and description thereof will be omitted.

[0101] The method for manufacturing a bonded body of the third embodiment further includes a pressurizing step. The pressurizing step may be performed either before or during the bonding step, but is preferably performed during the bonding step. In the pressurizing step, pressure is applied in the direction in which the sintered body and the object are bonded. The direction in which the sintered body and the object are bonded is the direction in which the bonding surface of the sintered body and the bonding surface of the object face each other when bonded. The pressurizing step is performed in the pressurizing step S12 shown in FIG. 15.

[0102] The pressing step may be performed by any method, for example, by placing a weight on the two overlapping members to be joined to apply surface pressure.

[0103] The pressure to be applied is not limited. However, if the pressure is too high, it may cause deformation depending on the shape of the members to be joined.

[0104] In the manufacturing method of the bonded body of the third embodiment, the pressurizing step is included, so that the bonded members come into close contact with each other during bonding, the liquid phase spreads well, and voids at the boundary interface of the bonded portion of the bonded body are reduced, thereby improving bondability.

[0105] <<Fourth embodiment>> Fig. 16 is a flow chart showing a method for manufacturing a bonded body according to a fourth embodiment of the present invention. In the fourth embodiment, parts common to the first, second and third embodiments are denoted by the same or corresponding reference numerals as those in Fig. 1, Fig. 10 and Fig. 15, and description thereof will be omitted.

[0106] The joined body of the fourth embodiment includes a sintered body, an object, and a brazing member. In the manufacturing method of the joined body of the fourth embodiment, the joining step also includes brazing the contacting surfaces of the object and the brazing member. Specifically, as shown in Fig. 16, in the joining step S2, the sintered body is heated in a temperature range where the sintered body generates a liquid phase, and the sintered body and the object are joined by direct contact with each other, while the object and the brazing member are joined.

[0107] In the fourth embodiment, the object and the brazing member are joined by the heat treatment in the joining step in a region different from the joining region where the sintered body and the object are joined. In the fourth embodiment, the region of the object where the object and the brazing member are joined is a region different from the joining region where the sintered body and the object are joined. In other words, the object and the brazing member are brought into contact with each other in a region different from the joining region where the sintered body and the object are joined by direct contact with each other.

[0108] The brazing member may be coated with a brazing material, or a brazing member to which a brazing material has been applied may be used. The brazing material is appropriately selected according to the object to be joined by brazing and the brazing member. Examples of brazing materials for aluminum include Toyal Hyper Braze (registered trademark) (manufactured by Toyo Aluminum Co., Ltd.) and XuperBraze 190PA (manufactured by Castolin Eutectic Co., Ltd.). The brazing material may contain flux, and when a brazing material containing flux is used, it is not necessary to apply flux to the brazing member.

[0109] The manufacturing method of the bonded body of the fourth embodiment uses an object cut to match the dimensions of the sintered body. After the sintering step S1, a dimension measuring step and a cutting step may be included. In the dimension measuring step, the dimensions of the sintered body are measured. Examples of measuring means for measuring the dimensions of the sintered body include a vernier caliper and a non-contact three-dimensional measuring machine (VL-500, manufactured by Keyence Corporation). In the cutting step, the object is cut to match the dimensions of the sintered body measured in the dimension measuring step.

[0110] In the cutting step, as shown in Fig. 17 to Fig. 19, a step 7A may be provided in a metal container 7, which is an example of an object, in accordance with the size of the sintered compact 6 to be joined. By providing the step 7A, the sintered compact 6 can be fixed to the step 7A of the metal container 7.

[0111] For example, as shown in Fig. 17 and Fig. 18, steps 7A may be provided on the entire two opposing sides of a roughly rectangular parallelepiped container 7, or steps 7A may be provided on some of the sides constituting the container 7 as shown in Fig. 19. Although one step 7A is provided on each side in Fig. 17 and Fig. 19, the number, location and shape of the steps 7A can be appropriately selected according to the shape and size of the sintered body. The container 7 in Fig. 18 is shown in the AA cross section of Fig. 17, and the sintered body 6 is fixed by the steps 7A.

[0112] 20 and 21, in the cutting process, a plurality of protrusions 7B may be provided on a metal container 7, which is an example of an object, in accordance with the joining positions of the sintered compact 6, and the protrusions 7B of the metal container 7 may be fitted into the depressions 6A provided in advance in the sintered compact 6. The container 7 in FIG. 21 is shown in the BB cross-sectional view of FIG. 20, and the sintered compact 6 is fixed by the protrusions 7B.

[0113] The shape, number and arrangement of the protrusions 7B are appropriately selected according to the shape and size of the depressions provided in the sintered body. By providing two or more depressions in the sintered body and providing the same number of depressions in the container 7 as there are depressions in the sintered body, more accurate joining can be achieved. By providing the steps 7A and protrusions 7B, the sintered body 6 can be joined to the target position on the container 7, and as a result, the joined part can function as designed.

[0114] In the brazing process, a brazing member 8 constituting a lid and a brazing material 9 are brought into contact with the upper surface of a container 7 as shown in Fig. 22, and the container is placed in a furnace. This results in a joined body in which the sintered body 6 is surrounded by the container 7 and the lid 8 to form a case, as shown in Fig. 23.

[0115] The cased assembly shown in Fig. 23 can be used, for example, as a heat sink. A heat sink is a device that performs cooling by dissipating (radiating) absorbed heat into the air. When the cased assembly shown in Fig. 23 is used as a heat sink, a cooling liquid such as water may be injected into the inside of the heat sink and circulated.

[0116] In the joining method of the fourth embodiment, the sintered body and the object are joined by direct contact with each other in this way, and at the same time, the object and the brazing member are joined, so that the desired joined body can be manufactured in one process. This makes it possible to use one heating device to join the sintered body 6 and the container 7 and to braze the container 7 and the lid 8, without having to prepare two separate heating devices. In addition, since the heat treatment is performed only once, the process time is also minimized.

[0117] By using such a cased joint body as a heat sink, the internal structure of the heat sink can be designed to be complex, thereby improving the cooling efficiency of the heat sink.

[0118] <<Fifth embodiment>> The manufacturing method of the bonded body according to the fifth embodiment of the present invention is performed according to the flow chart shown in Fig. 16. The manufacturing method of the bonded body according to the fifth embodiment differs from the fourth embodiment in that an object obtained by press working is used. In the fifth embodiment, the parts common to the first, second, third and fourth embodiments are denoted by the same or corresponding reference numerals as those in Figs. 1, 10, 15 and 16, and the description thereof will be omitted.

[0119] The joined body of the fifth embodiment also has a sintered body, an object, and a brazing member. In the manufacturing method of the joined body of the fifth embodiment, similarly to the fourth embodiment of FIG. 16, in the joining step, the contacting surfaces of the object and the brazing member are joined by brazing. The region of the object where the object and the brazing member are joined is a region different from the joining region where the sintered body and the object are joined. In other words, the object and the brazing member are brought into contact with each other in a region different from the joining region where the sintered body and the object are joined by direct contact.

[0120] In the fifth embodiment, as shown in Fig. 16, in the joining step S2, when the sintered body is heated in a temperature range where the sintered body generates a liquid phase, the sintered body and the object are directly brought into contact with each other to join them, and at the same time, the object and the brazing member are joined together. The object and the brazing member are in contact with each other via a brazing material. In the joining step, the contacting surfaces of the object and the brazing member are joined by brazing.

[0121] In the fifth embodiment, the object and the brazing member are joined by the heat treatment in the joining step in a region different from the joining region where the sintered body and the object are joined. The manufacturing method of the joined body of the fifth embodiment uses an object obtained by pressing a metal plate. Before the sintering step S1, a metal plate forming step, a distortion measuring step, and a precursor producing step may be included.

[0122] In the sheet metal forming process, a sheet metal is pressed to produce an object. In the press process, an object having steps or protrusions may be produced. The press process may include, for example, bending. In the distortion measurement process, the dimensions of the object obtained by the press process are measured. In the precursor production process, a precursor is produced according to the distortion of the object measured in the distortion measurement process.

[0123] By using an object produced by pressing a metal plate, the cost can be reduced compared to producing an object by cutting. In addition, the object and the brazing member used in the manufacturing method of the joined body of the fifth embodiment may be the same. Fig. 25 shows a joined body according to the fifth embodiment in which the object and the brazing member are integrated.

[0124] FIG. 24 is a flow chart showing a method for manufacturing the joined body shown in FIG. 25. In FIG. 25, one region of the object and another region of the object are joined by brazing in a region different from the joining region where the sintered body and the object are joined by heat treatment in the joining process. In the fifth embodiment of FIG. 25, as shown in FIG. 24, in the joining process, one region of the object and another region are also joined by brazing in parallel with the joining of the sintered body and the object. The region joined by brazing and the region where the sintered body and the object are joined are different. In the sheet metal forming process, the container 7 and the lid 8 are integrally formed, so that the object and the brazing member can be the same. In the joined body of FIG. 25, the sintered body 6 is cased in the container 7 with the lid integrally formed.

[0125] In the joining method of the fifth embodiment, the sintered body and the object are joined by directly contacting and joining them, and at the same time, the object and the brazing member are joined, so that the desired joined body can be formed in a short process. This makes it possible to perform multiple heat treatments, which would otherwise be extremely costly, in one device, and therefore prevents a huge increase in manufacturing costs.

[0126] <zygote> The bonded body according to one embodiment of the present invention is a bonded body in which a sintered body and an object are directly bonded to each other. The bonded body according to this embodiment can be obtained by the above-mentioned manufacturing method of the bonded body according to this embodiment.

[0127] In the joined body of the present embodiment, the sintered body contains an alloy. The elements contained in the alloy are not particularly limited, and are, for example, metal elements selected from aluminum (Al), iron (Fe), titanium (Ti), copper (Cu), silver (Ag), gold (Au), magnesium (Mg), calcium (Ca), zinc (Zn), and the like. The alloy is preferably an Al alloy. The Al alloy is more preferably an AlSi alloy or an AlSiMg alloy.

[0128] Fig. 26 is an enlarged view of a sintered body according to one embodiment of the present invention. Fig. 26 corresponds to an enlarged view of a cross section of the sintered body 3 included in the bonded body 2 shown in Fig. 6. The sintered body included in the bonded body has crystal grains C surrounded by eutectic E. The average diameter of the crystal grains C included in the bonded body is 10 µm or more, preferably 50 µm or more, and more preferably 90 µm or more. The average diameter of the crystal grains C is 500 µm or less, preferably 400 µm or less, and more preferably 200 µm or less.

[0129] Here, the average diameter of the crystal grains contained in the bonded body is the average of the grain diameters of the crystal grains. The grain diameter of the crystal grains may be confirmed by any method. For example, a cross section in the thickness direction may be observed by an optical microscope, a scanning electron microscope (SEM) or a transmission electron microscope (TEM), or analyzed by electron backscattered diffraction (EBSD).

[0130] By making the average grain size of the sintered body contained in the bonded body 90 μm or more and 500 μm or less, the sintered bodies can be bonded with good bonding quality. In addition, deformation of the objects during bonding can be suppressed.

[0131] Fig. 27 is a diagram showing a first modified example of a bonded body according to an embodiment of the present invention. Fig. 28 is a diagram showing a second modified example of a bonded body according to an embodiment of the present invention. Fig. 29 is a diagram showing a third modified example of a bonded body according to an embodiment of the present invention. In Figs. 27 to 29, parts common to those in Fig. 6 are given the same or corresponding reference numerals as in Fig. 6, and description thereof will be omitted.

[0132] The joined body 2B shown in Fig. 27 and the joined body 2C shown in Fig. 28 are both joined in a state where the sintered body 3 is inserted into an object 4 having a recess. The joined body 2C shown in Fig. 28 differs from the joined body 2B shown in Fig. 27 in that the sintered body 3 is also joined to the upper surface of the recess of the object 4. The joined body 2D shown in Fig. 29 has a cavity inside the object, and the sintered body is inserted into this cavity.

[0133] 27 to 29 also include a joint 5 which is a boundary between the sintered compact 3 and the object 4, as in Fig. 12. In addition, the eutectic E melted from the sintered compact 3 penetrates into the object 4, and the sintered compact 3 and the object 4 are joined together.

[0134] In the joined body of the present embodiment, the sintered body contains two or more metal elements, and the sintered body has a crystal portion and a crystal grain surrounded by a eutectic portion. As a result, the solid phase of the metal crystal portion is maintained during sintering, so that the entire sintered body is less likely to deform and the shape of the sintered body is maintained.

[0135] Furthermore, by making the average crystal grain size 10 μm or more, the sintered body as a whole is less likely to deform, and the shape of the sintered body is more likely to be maintained.

[0136] Furthermore, since the crystal grains contain aluminum elements and the eutectic portion contains aluminum elements and silicon elements, the entire sintered body is more resistant to deformation and the shape of the sintered body is maintained.

[0137] In addition, when the eutectic portion unevenly distributed in the sintered body is liquefied, the oxide film that exists on the metal surface and is a factor of sintering inhibition is destroyed, so there is no need to apply flux for the purpose of removing the oxide film. Therefore, the bonded body of this embodiment does not contain impurities such as flux at the interface. In addition, the bonded body of this embodiment has excellent adhesive strength between the sintered body and the object because there is no flux between the sintered body and the object.

[0138] <object> In the joined body according to one embodiment of the present invention, the object means a structure to be joined with the sintered body, and by joining with the sintered body, the shape, strength, etc. suitable for the desired use of the joined body are added. The melting point of the object is preferably equal to or higher than the melting point of the sintered body. By having the melting point of the object equal to or higher than the melting point of the sintered body, deformation of the object during joining can be suppressed.

[0139] The melting point of the object is preferably equal to or higher than the melting point of the alloy constituting the sintered body.

[0140] In this specification, the melting point refers to the temperature at which the liquid phase begins to form, as measured by thermodynamic calculation. The thermodynamic calculation can be performed, for example, using thermodynamic equilibrium calculation software (CaTCalc, manufactured by the Institute of Computational Thermodynamics).

[0141] Examples of materials constituting the object include metals and ceramics. Examples of metals include aluminum (Al), iron (Fe), titanium (Ti), copper (Cu), silver (Ag), gold (Au), magnesium (Mg), calcium (Ca), and zinc (Zn). Examples of ceramics include alumina (Al2O3), silicon nitride (Si3N4), zirconium oxide (ZrO2), and aluminum nitride (AlN). When the sintered body contains an aluminum alloy, it is preferable that the object contains an aluminum alloy. When the object contains an aluminum alloy, it becomes possible to bond the objects with good bonding quality.

[0142] In the joined body according to an embodiment of the present invention, the sintered body is contained in a housing having at least an object. The housing corresponds to, for example, the container 7 and the lid 8 constituting the cased joined body shown in Fig. 23 described above. The joined body containing the sintered body corresponds to the cased joined body shown in Fig. 23 described above.

[0143] The bonded body of the present embodiment can be used as a heat sink by including the sintered body in a housing that includes at least an object.

[0144] The heat sink formed by the bonded body of this embodiment can have a complex internal structure, and therefore the cooling efficiency of the heat sink can be improved.

[0145] Fig. 30 is a schematic diagram of an optical microscope photograph showing a cross section near the bonded boundary of a bonded body according to still another embodiment of the present invention (wherein the object bonded to the sintered body is ceramics). In Fig. 30, parts corresponding to Fig. 11 are given reference numerals that are 100 larger than the reference numerals given in Fig. 11, and explanations thereof are omitted. In Fig. 30, a cross section near the bonded boundary of the bonded body is shown so that the sintered body is shown at the top of the drawing, while the object at the bottom of the drawing is made of a ceramic plate.

[0146] 30, in the bonding between the sintered body 103 and the object 104 (ceramics), the eutectic portion also becomes liquid and diffuses into the ceramic side. That is, in the bonding between the ceramic and the sintered body, the sintered body becomes liquid preferentially, and the bonding proceeds while maintaining the shape of the bonded body, as in the bonding between the object containing a metal or alloy and the sintered body.

[0147] In addition, when the object to be joined to the sintered body contains a metal or alloy, as described above, diffusion of eutectic E is observed inside the object as well. However, when the object to be joined to the sintered body is a ceramic, eutectic E does not diffuse into the inside of the ceramic, and the liquid phase merely penetrates into the unevenness of the ceramic surface at the boundary 105 between the sintered body 103 and the object 104.

[0148] As described above, in the bonded body according to the further embodiment of the present invention, the shape of the sintered body 103 is maintained in a state where the sintered body 103 is fixed to the surface of the object 104 by the anchor effect. Therefore, even when the sintered body and the ceramic are bonded to each other, the entire sintered body is not deformed, and bonding can be performed while maintaining the shape of the sintered body. EXAMPLES

[0149] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the following, "%" is based on mass unless otherwise specified. In addition, various tests and evaluations were performed according to the following methods.

[0150] <Preparation of the junction> The bonded bodies were prepared by bonding a sintered body obtained by sintering a precursor with a rolled body (Examples 1-5, 8-13), bonding two sintered bodies together (Examples 6, 7), bonding a sintered body with a ceramic (Examples 14, 15), and bonding two rolled bodies together (Comparative Examples 1-4). The bonded conditions and bonding quality of each bonded body are shown in Tables 1 and 2.

[0151] [Table 1]

[0152] [Table 2]

[0153] <Average grain size> The average grain size in a sintered body is mainly measured by observation under an optical microscope. For the measurement of the average grain size, 20 grains were selected from one cross-sectional photograph taken under an optical microscope, and their dimensions in two perpendicular directions, the X-direction and the Y-direction, were measured. The grain sizes were similarly measured from 10 micrographs, and the average of the dimensions of a total of 200 grains was calculated, which was taken as the average grain size.

[0154] <Liquid phase occurrence rate during bonding> The liquid phase generation rate was calculated by thermodynamic calculation based on the alloy composition. The liquid phase generation rate was estimated by inputting the alloy composition of the powder and the joining treatment temperature into thermodynamic equilibrium calculation software (CaTCalc, manufactured by Computational Thermodynamics Institute, Inc.).

[0155] <Joining quality> The quality of the conjugate is evaluated according to the following criteria. Excellent: No distortion of the joint or gaps in the joint were observed. Good: A small gap was observed at the joint, but no distortion of the joint was observed, or a small distortion was observed at the joint, but no gap was observed at the joint. Unacceptable: The joint was not joined, or gaps and significant distortion were observed at the joint.

[0156] [Example 1] A sintered body was prepared by sintering the precursor, and a bonded body was prepared by bonding a rolled body as an object. The size of the sintered body and the rolled body was 50 mm x 50 mm x 10 mm, respectively. The precursor was made of aluminum-silicon (AlSi) alloy powder (manufactured by Toyo Aluminum Co., Ltd.) molded by BJT using the molding device shown in Figure 3. The sintering time of the precursor was medium (4 hours). The average diameter of the crystal grains of the sintered body was 200 μm. The rolled body was made by rolling a cast body obtained by melting aluminum-silicon-magnesium (AlSiMg) alloy powder (manufactured by Misumi Co., Ltd., aluminum free plate A6061). The bonding surfaces of the sintered body and the rolled body were cut (smoothed) with a milling cutter. The bonding temperature was 575°C to 610°C. The liquid phase generation rate during bonding was medium (20 mass%).

[0157] [Example 2] A bonded body was produced and evaluated in the same manner as in Example 1, except that the sintering time of the precursor was short (2 hours) and the average crystal grain size of the sintered body was 100 μm.

[0158] [Example 3] A bonded body was produced and evaluated in the same manner as in Example 1, except that the sintering time of the precursor was long (10 hours) and the average crystal grain size of the sintered body was 400 μm.

[0159] [Example 4] A bonded body was produced and evaluated in the same manner as in Example 1, except that the bonding treatment temperature was set to 620° C. to 640° C. and the liquid phase generation rate during bonding was large (50 mass %).

[0160] [Example 5] A bonded body was produced and evaluated in the same manner as in Example 1, except that copper (C1100) powder was used for the rolled body.

[0161] [Example 6] A joined body was produced and evaluated in the same manner as in Example 1, except that sintered bodies were joined together instead of joining a sintered body and a rolled body.

[0162] [Example 7] A bonded body was produced and evaluated in the same manner as in Example 6, except that the bonding surfaces of the sintered bodies to be bonded were not subjected to a smoothing treatment.

[0163] [Example 8] A bonded body was produced and evaluated in the same manner as in Example 1, except that an aluminum-silicon-magnesium (AlSiMg) alloy powder was used for the sintered body and the bonding treatment temperature was set to 565°C to 600°C.

[0164] [Example 9] A bonded body was produced and evaluated in the same manner as in Example 8, except that a precursor obtained by shaping aluminum-silicon-magnesium (AlSiMg) alloy powder (manufactured by Toyo Aluminum Co., Ltd.) by MIM and sintering it was used as the sintered body.

[0165] [Example 10] A bonded body was produced and evaluated in the same manner as in Example 1, except that an aluminum-magnesium (AlSiMg) alloy powder was used for the rolled body.

[0166] [Example 11] A sintered body was prepared by sintering the precursor, and a joint was prepared by joining a rolled body as the case part and a rolled body as the lid part. The size of the sintered body was 45mm x 45mm x 6mm, the size (outer dimensions) of the rolled body of the case part was 60mm x 60mm x 8mm, and the size of the rolled body of the lid part was 60mm x 60mm x 1.5mm. The precursor was made of aluminum-silicon (AlSi) alloy powder (manufactured by Toyo Aluminum Co., Ltd.) molded with a BJT using the molding device shown in Figure 3. The sintering time of the precursor was medium (4 hours). The average diameter of the crystal grains of the sintered body was 200μm. The rolled body of the case part was made by rolling a cast body obtained by melting aluminum-silicon-magnesium (AlSiMg) alloy powder (manufactured by Misumi Co., Ltd., Aluminum Free Plate A6061), and the rolled body of the lid part was made by rolling aluminum. The joint surfaces of the sintered body and the rolled body were cut (smoothed) by a milling cutter. The joining temperature was 575°C to 610°C. The liquid phase generation rate during joining was medium (20 mass%). The sintered body and the rolled body of the case were in direct contact with each other, and the rolled body of the case and the rolled body of the lid were joined by applying brazing material. The rolled bodies were brazed together using brazing material (Toyal Hyper Braze, manufactured by Toyo Aluminum).

[0167] [Example 12] A joint was produced and evaluated in the same manner as in Example 11, except that a rolled aluminum body was used for the case part (container 7) of the rolled body, and a brazing sheet having an aluminum-manganese (AlMn) alloy clad with an aluminum-silicon (AlSi) alloy and a brazing material layer was used for the lid part (lid 8).

[0168] [Example 13] A joint body was produced and evaluated in the same manner as in Example 12, except that a pressed product of an aluminum-manganese (AlMn) alloy plate material was used for the case portion (container 7) of the rolled body.

[0169] [Example 14] A bonded body was produced and evaluated in the same manner as in Example 1, except that an alumina (Al2O3) plate was bonded to the sintered body instead of the rolled body.

[0170] [Example 15] A bonded body was produced and evaluated in the same manner as in Example 1, except that a silicon nitride plate (Si3N4) was bonded to the sintered body instead of the rolled body.

[0171] [Comparative Example 1] Instead of joining a sintered body and a rolled body, rolled bodies were joined together, and a joined body was produced in the same manner as in Example 8 and evaluated.

[0172] [Comparative Example 2] A bonded body was produced and evaluated in the same manner as in Comparative Example 1, except that the bonding treatment temperature was set to 610° C. to 630° C. and the liquid phase generation rate during bonding was large (50 mass %).

[0173] [Comparative Example 3] A bonded body was produced and evaluated in the same manner as in Comparative Example 1, except that the bonding treatment temperature was set to 575°C to 610°C.

[0174] [Comparative Example 4] A bonded body was produced and evaluated in the same manner as in Comparative Example 2, except that the bonding treatment temperature was set to 620°C to 640°C.

[0175] As shown in Table 1, the sintered bodies obtained by sintering precursors composed of powders containing two or more elements, as in Examples 1 to 15, all had an average crystal grain size of 10 μm or more. In addition, the joined bodies obtained by joining the sintered bodies of Examples 6 and 7, the joined bodies obtained by joining the sintered body and the rolled body of Examples 1 to 5 and 8 to 13, and the joined bodies obtained by joining the sintered body and the ceramics of Examples 14 and 15 all had good joining quality.

[0176] On the other hand, as can be seen from Table 2, in the cases of Comparative Examples 1 to 4 in which the rolled bodies were joined to each other, the rolled bodies were not joined, and the deformation of the rolled bodies after joining was large, and the joining quality was not good.

[0177] Furthermore, as can be seen from Table 1, in Examples 11 to 13, bonding with the brazing material can be performed simultaneously, making it possible to form the desired bonded body in a short process.

[0178] Embodiments of the present invention include, for example, the following aspects.

[0179] <1> a joining step of directly contacting the sintered body with an object and heat-treating the same to obtain a joined body; The method for producing a joined body, wherein the sintered body contains an alloy.

[0180] <2> The heat treatment is a treatment of heating the sintered body in a temperature range in which a liquid phase is generated in the sintered body. <1> A method for producing the bonded body according to claim 1.

[0181] <3> The method includes a smoothing step of smoothing at least one of the joining surfaces of the sintered body and the object before the joining step. <1> or <2> A method for producing the bonded body according to claim 1.

[0182] <4> The method includes a pressurizing step of applying pressure to the sintered body and the object in a direction in which the sintered body and the object are joined together before or during the joining step. <1> ~ <3> 13. A method for producing the bonded body according to claim 12.

[0183] <5> A sintering step is provided before the joining step, in which a precursor containing two or more elements including at least one metal element is sintered, The precursor is a shaped object shaped by an additive manufacturing method. <1> ~ <4> 13. A method for producing the bonded body according to claim 12.

[0184] <6> The additive manufacturing method is a binder jetting method. <5> A method for producing the bonded body according to claim 1.

[0185] <7> The alloy is an aluminum alloy. <1> ~ <6> 13. A method for producing the bonded body according to claim 12.

[0186] <8> The joining step heats the sintered body in a temperature range in which a liquid phase of 5 mass % or more and 50 mass % or less occurs in the sintered body. <1> ~ <7> 13. A method for producing the bonded body according to claim 12.

[0187] <9> The sintered body includes a eutectic portion and crystal grains surrounded by the eutectic portion, The crystal grains contain aluminum elements, The eutectic portion has an aluminum element and a silicon element. The above <1> ~ <8> 13. A method for producing the bonded body according to claim 12.

[0188] <10> The melting point of the object is equal to or higher than the melting point of the sintered body. <1> ~ <9> 13. A method for producing the bonded body according to claim 12.

[0189] <11> The object and the brazing member are joined in a region different from a joining region where the sintered body and the object are joined by the heat treatment in the joining step. <1> ~ <10> 13. A method for producing the bonded body according to claim 12.

[0190] <12> By the heat treatment in the joining step, one region of the object is joined to another region of the object in a region different from a joining region where the sintered body and the object are joined. <1> ~ <10> 13. A method for producing the bonded body according to claim 12.

[0191] <13> A bonded body in which a sintered body and an object are directly bonded, The sintered body includes an alloy containing two or more elements and has crystal grains surrounded by a eutectic portion, The bonded body, wherein the average diameter of the crystal grains is 10 μm or more.

[0192] <14> The average diameter of the crystal grains is 10 μm or more and 500 μm or less. <13> The conjugate according to claim 1,

[0193] <15> The alloy is an aluminum alloy. <13> or <14> The conjugate according to claim 1,

[0194] <16> The sintered body is contained in a housing having at least the object. <13> ~ <15> 13. The conjugate according to any one of claims 1 to 12.

[0195] <17> The above <13> ~ <16> A heat sink having the joint according to any one of the above. [Explanation of symbols]

[0196] 1 Modeling system 100 Modeling equipment 400 Sintering Equipment 2, 2A, 2B, 2C, 2D zygote 3. Sintered body 4 objects 5 Joint 6 Sintered body 7 containers 7A step 7B protrusion 8 Lid 9 Brazing material 10 Joint C grain E eutectic part Gyroid structure [Prior art documents] [Patent documents]

[0197] [Patent Document 1] Patent No. 6218903

Claims

1. a joining step of directly contacting the sintered body with an object and heat-treating the same to obtain a joined body; The method for producing a joined body, wherein the sintered body contains an alloy.

2. The method for producing a bonded body according to claim 1 , wherein the heat treatment is a treatment of heating the sintered body in a temperature range where a liquid phase is generated in the sintered body.

3. The method for producing a joint body according to claim 1 , further comprising a smoothing step of smoothing the joining surfaces of at least one of the sintered body and the object prior to the joining step.

4. The method for producing a bonded body according to claim 1 , further comprising a pressurizing step of applying pressure in a direction in which the sintered body and the object are bonded together, before or during the bonding step.

5. A sintering step is provided before the joining step, in which a precursor containing two or more elements including at least one metal element is sintered, The method for producing a bonded body according to claim 1 , wherein the precursor is a shaped object produced by an additive manufacturing method.

6. The method for producing a bonded body according to claim 5 , wherein the additive manufacturing method is a binder jetting method.

7. The method for producing a joint body according to claim 1 , wherein the alloy is an aluminum alloy.

8. The method for producing a bonded body according to claim 2 , wherein the bonding step comprises heating the sintered body in a temperature range in which a liquid phase is generated in an amount of 5 mass % or more and 50 mass % or less in the sintered body.

9. The sintered body includes a eutectic portion and crystal grains surrounded by the eutectic portion, The crystal grains contain aluminum elements, The method for producing a joint body according to claim 7 , wherein the eutectic portion contains aluminum elements and silicon elements.

10. The method for producing a joint body according to claim 1 , wherein the melting point of the object is equal to or higher than the melting point of the sintered body.

11. The method for manufacturing a joined body according to claim 1 , wherein the heat treatment in the joining step joins the body and the brazing member in a region different from a joining region where the sintered body and the body are joined.

12. The method for manufacturing a joined body according to claim 1 , wherein the heat treatment in the joining step joins one region of the object to another region of the object in a region different from a joining region that joins the sintered body to the object.

13. A bonded body in which a sintered body and an object are directly bonded, the sintered body includes an alloy and has crystal grains surrounded by a eutectic portion; The average diameter of the crystal grains is 10 μm or more.

14. The bonded body according to claim 13, wherein the average diameter of the crystal grains is 10 μm or more and 500 μm or less.

15. The joint of claim 13, wherein the alloy is an aluminum alloy.

16. The joined body according to claim 13 , wherein the sintered body is contained in a housing that includes at least the object.

17. A heat sink comprising an assembly according to any one of claims 13 to 16.

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