Method for manufacturing a joint between solid metals and a composite member

Abstract

The present invention provides a method for manufacturing a jointed body of solid metals and a composite member that can increase the bonding strength at the joint surface. [Solution] A solid metal body containing a first component is brought into contact with a solid metal material consisting of a compound, alloy, or non-equilibrium alloy that simultaneously contains a second component and a third component, each having positive and negative mixing heats relative to the first component, respectively. A predetermined pressure is applied between the metal body and the metal material while performing heat treatment at a predetermined temperature for a predetermined time. This causes the first component and the third component to mutually diffuse, and the alloy liquid containing the first component and the third component, which is generated in the region where the first component and the third component have mutually diffused, is discharged.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a joined body of metal solids and a composite member.

Background Art

[0002] Conventionally, as a method for manufacturing a joined body of metal solids, the present inventors have developed a de-composition method in which a solid metal body composed of a first component is brought into contact with a solid metal material composed of a compound, an alloy or a non-equilibrium alloy containing a second component and a third component having positive and negative mixing heats with respect to the first component, respectively, and heat treatment is performed at a predetermined temperature for a predetermined time to cause mutual diffusion of the first component and the third component (see, for example, Patent Document 1). This method is a method for manufacturing a nano-composite metal member based on a metallurgical technique. However, since the first component in the metal body and the third component in the metal material mutually diffuse by heat treatment and the metal body and the metal material are joined, it can also be used as a method for manufacturing a joined body of metal solids.

[0003] As an example of performing joining using the de-composition method described in Patent Document 1, for example, the present inventors have joined iron (Fe) and magnesium (Mg) that do not mix with each other (see, for example, Non-Patent Document 1). That is, on the surface of Fe, an Fe 100-x Ni x layer is joined by diffusion bonding, and Fe 100-x Ni x layer is sandwiched, and Mg is brought into contact with the surface of the Fe 100-x Ni x layer, and then Fe 100-x Ni x layer and Mg are joined by the method described in Patent Document 1 to join Fe and Mg.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Non-Patent Literature

[0005]

Non-Patent Literature 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the joining of Fe and Mg described in Non-Patent Literature 1, when the Fe 100-x Ni x layer contains sufficient Ni (x > 30, the value is at%), it has been confirmed that Ni and Mg diffuse into each other between the Fe 100-x Ni x layer and Mg to form a composite metal member. However, when 30 < x < 50, a high joining strength can be obtained, but when x > 60, a large amount of brittle intermetallic compound Mg2Ni is formed, resulting in a problem that the joining strength at the joining surface becomes small.

[0007] The present invention has been made by paying attention to such problems, and an object thereof is to provide a method for manufacturing a joined body of metal solids and a composite member that can increase the joining strength at the joining surface.

Means for Solving the Problems

[0008] To achieve the above objective, the present inventors investigated in detail the reaction process of the decomposition method described in Patent Document 1 in the joining described in Non-Patent Document 1. They found that, upon heat treatment, the first component (Mg) of the metal body and the third component (Ni) of the metal member (FeNi) undergo a eutectic reaction, causing the contact surface to melt and generating a liquid (Mg-Ni liquid) containing the first and third components. As a result, the decomposition reaction proceeds rapidly as a liquid-phase diffusion with high diffusivity. Based on this finding, the present inventors conducted further investigations and arrived at the present invention.

[0009] In other words, the method for manufacturing a joint of solid metals according to the present invention is characterized by bringing a solid metal body containing a first component into contact with a solid metal material consisting of a compound, alloy, or non-equilibrium alloy that simultaneously contains a second component and a third component having positive and negative mixing heats with respect to the first component, respectively, and applying a predetermined pressure between the metal body and the metal material while performing heat treatment at a predetermined temperature for a predetermined time, thereby causing the first component and the third component to interdiffuse, and discharging the alloy liquid containing the first component and the third component that is generated in the region where the first component and the third component have interdiffused.

[0010] The present invention relates to a method for manufacturing a bonded metal-solid body, in which a solid metal body and a solid metal material are brought into contact and heat-treated, causing mutual diffusion of a third component from the metal material to the metal body and a first component from the metal body to the metal material, depending on the heat of mixing with the first component of the metal body. The second component does not diffuse to the metal body side. As a result, in the region of the metal material where the first and third components have mutually diffused, a co-continuous structure can be formed in which the portion containing the first and third components and the portion containing the second component are finely intertwined on the order of nanometers or micrometers.

[0011] Furthermore, by using a third component that undergoes a eutectic reaction with the first component at a predetermined temperature, the first and third components undergo a eutectic reaction in the region where they mutually diffuse, resulting in the formation of an alloy liquid containing the first and third components. If this alloy liquid remains and solidifies, it becomes brittle, reducing the bonding strength at the joint between the metal body and the metal material. Therefore, in the method for manufacturing a joint between solid metals according to the present invention, the generated alloy liquid is discharged to the outside by applying a predetermined pressure while performing heat treatment, thereby preventing a decrease in bonding strength at the joint. Thus, the method for manufacturing a joint between solid metals according to the present invention can increase bonding strength compared to the case where no predetermined pressure is applied. In addition, since the alloy liquid, which becomes brittle when solidified, is discharged to the outside, ductility can also be increased.

[0012] Furthermore, in the method for manufacturing a bonded metal solid according to the present invention, the contact area between the metal body and the metal material melts due to a eutectic reaction between the first component and the third component, allowing the interdiffusion between the first component and the third component to occur in the liquid phase. This allows the interdiffusion between the first component and the third component to proceed more rapidly, and the bonding time can be shortened compared to solid-phase diffusion.

[0013] In the method for manufacturing a bonded metal solid body according to the present invention, the alloy liquid preferably does not contain a second component, and may contain components other than the second component in addition to the first and third components. Furthermore, the alloy liquid preferably has a melting point or liquidus temperature lower than the melting point of the metal body so that it is formed when the solid metal body and the solid metal material are brought into contact. The alloy liquid may, for example, contain a material that, when solidified, forms an intermetallic compound in which the first component and the third component are bonded together.

[0014] The method for manufacturing a bonded metal solid according to the present invention utilizes interdiffusion due to eutectic reactions between solids, eliminating the need to heat the metal body or metal material above its melting point. Therefore, the predetermined temperature during heat treatment is preferably lower than the melting points of the metal body and metal material, and higher than the melting point or liquidus temperature of the alloy liquid. This allows for a reduction in the heating temperature required for joining, compared to heating above the melting point, thereby reducing the time and cost required for heating.

[0015] In the method for manufacturing a joint between solid metals according to the present invention, the predetermined pressure is preferably 10 MPa or higher, and more preferably 20 MPa or higher. This allows for the discharge of more alloy liquid to the outside, reduces the amount of residual alloy liquid, and increases the joint strength. The alloy liquid is preferably discharged from the region where the third component on the metal body side is diffused, within the region where the first component and the third component have mutually diffused, that is, from the boundary between the region on the metal body side that does not contain the third component and the region that contains the third component, to the boundary (joint surface) between the metal body and the metal material. After discharge, the alloy liquid may adhere to the periphery of the joint formed by the joining of the metal body and the metal material.

[0016] The present invention relates to a method for manufacturing a bonded body of solid metals, wherein the first component consists of one or more of Li, Mg, Ca, Cu, Zn, Ag, Pb, Bi, and rare earth metal elements, the metal body consists of only the first component, or a mixed body which is an alloy, compound, or non-equilibrium alloy mainly composed of the first component, the second component consists of one or more of Ti, Zr, Hf, Nb, Ta, Cr, V, Mo, W, Fe, Co, Ni, C, Si, Ge, and Sn, the third component consists of one or more of Li, Mg, Ca, Mn, Fe, Co, Ni, Cu, Ti, Zr, Hf, Nb, Ta, Cr, Mo, and W, and the metal material preferably consists of a mixed body which is an alloy, compound, or non-equilibrium alloy which simultaneously contains the second component and the third component.

[0017] Specifically, for example, the first component may consist of Mg, the metal body may consist of only the first component, or a mixed alloy, compound, or non-equilibrium alloy mainly composed of the first component, the third component may consist of Ni, and the metal material may be an Fe-containing alloy. Alternatively, the first component may consist of Mg, the metal body may consist of only the first component, or a mixed alloy, compound, or non-equilibrium alloy mainly composed of the first component, the third component may consist of Cu, and the metal material may be a Ti-containing alloy. Note that the main component is the component that is present in the largest quantity among the components contained in the metal body or metal material.

[0018] The method for manufacturing a joint of solid metals according to the present invention utilizes interdiffusion between solids to join solid metals that are normally difficult to join. Furthermore, for two solid metals that cannot be directly joined, one solid metal can be prepared by forming a metal body and joining a metal material to the surface of the other solid metal, and then joining the metal body and the metal material using the method for manufacturing a joint of solid metals according to the present invention to join the two solid metals. Alternatively, after joining the metal body (one solid metal) and the metal material, the other solid metal may be joined to the metal material.

[0019] The present invention provides a method for manufacturing a composite material made of solid metals, which allows for the production of a composite material having a co-continuous structure in which the portion composed of the first and third components and the portion composed of the second component are finely intertwined on a nanometer or micrometer order in the region of the metal material where the first and third components have interdiffused with each other.

[0020] The method for manufacturing a joined body according to the present invention is characterized by bringing a solid metal body containing Mg or an Mg alloy into contact with a solid metal material containing an alloy of Ni and Fe, or an alloy of Ti and Cu, and joining the metal body and the metal material by applying pressure between the metal body and the metal material while heating the metal body and the metal material.

[0021] The method for manufacturing a bonded body according to the present invention involves bringing a solid metal body and a solid metal material into contact and performing heat treatment, which causes Ni or Cu to interdiffuse from the metal material to the metal body, and Mg to interdiffuse from the metal body to the metal material. Ti, however, does not diffuse into the metal body. As a result, in the region of the metal material where Mg and Ni or Cu have interdiffused, a co-continuous structure can be formed in which the portions containing Mg and Ni or Cu and the portions containing Ti are finely intertwined on the order of nanometers or micrometers.

[0022] Furthermore, in the region where Mg and Ni or Cu interdiffuse, a eutectic reaction occurs between Mg and Ni or Cu, producing an alloy liquid containing Mg and Ni or Cu. When this alloy liquid solidifies, it becomes brittle, reducing the bonding strength at the joint between the metal body and the metal material. Therefore, in the method for manufacturing a joined body according to the present invention, by applying pressure while performing heat treatment, the resulting alloy liquid can be discharged to the outside, preventing a decrease in bonding strength at the joint and increasing the bonding strength. It can also increase ductility.

[0023] Furthermore, in the method for manufacturing a bonded body according to the present invention, Mg and Ni or Cu undergo a eutectic reaction, and the contact area between the metal body and the metal material melts, allowing the interdiffusion of Mg and Ni or Cu to occur in the liquid phase. This allows the interdiffusion of Mg and Ni or Cu to proceed more rapidly, and the bonding time can be shortened compared to solid-phase diffusion.

[0024] In the method for manufacturing a bonded body according to the present invention, the metal body is an alloy containing Mg, Zn, and Y or Zr, or an alloy containing Mg, Al, and Zn, and the metal material is Fe 100-x Ni x (30 ≤ x ≤ 70, values ​​are in at%), or Ti 100-y Cu y (30 ≤ y ≤ 70, the numerical value may include at%).

[0025] Furthermore, in the method for manufacturing a joint according to the present invention, an Fe alloy or Ti alloy may be joined to the metal material such that the metal material is sandwiched between the metal body. In this case, solid metals that cannot be directly joined can be joined together via the metal material sandwiched in between. Also, of the two solid metals that are joined with the metal material sandwiched in between, either one may be joined first. Furthermore, the Fe alloy is preferably carbon steel or stainless steel. Furthermore, the Ti alloy is preferably Ti and at least one of Al, V, Nb, Ni, Cr, and Sn.

[0026] Furthermore, the method for manufacturing a joint according to the present invention may also involve joining a metal or alloy containing at least one of Mg, Zn, Y, Zr, and Al, having a different composition from the metal material, to the metal material, with the metal body sandwiched between them. In this case as well, solid metals that cannot be directly joined can be joined together via the metal body sandwiched in between. Moreover, either of the two solid metals joined with the metal body sandwiched in between may be joined first.

[0027] The composite member according to the present invention has a co-continuous structure in which a solid metal body containing a first component, a portion having a third component having a negative heat of mixing with respect to the first component and the first component, and a portion having a second component having a positive heat of mixing with respect to the first component are intertwined on the order of nanometers or micrometers, and the co-continuous structure is bonded to the surface of the metal body.

[0028] In the composite member according to the present invention, it is preferable that the third component is composed of a material that undergoes a eutectic reaction with the first component at a temperature lower than the melting point of the metal body. Furthermore, in the composite member according to the present invention, it is preferable that the first component consists of one or more of Li, Mg, Ca, Cu, Zn, Ag, Pb, Bi, and rare earth metal elements, the metal body consists of only the first component, or a mixed material which is an alloy, compound, or non-equilibrium alloy mainly composed of the first component, the second component consists of one or more of Ti, Zr, Hf, Nb, Ta, Cr, V, Mo, W, Fe, Co, Ni, C, Si, Ge, and Sn, and the third component consists of one or more of Li, Mg, Ca, Mn, Fe, Co, Ni, Cu, Ti, Zr, Hf, Nb, Ta, Cr, Mo, and W.

[0029] The composite member according to the present invention comprises a solid metallic material consisting of a compound, alloy, or non-equilibrium alloy containing both the second and third components, wherein the metallic material may be joined to the metallic body with the co-continuous structure in between.

[0030] In the case of this metallic material, the first component may consist of Mg, the metallic body may consist of only the first component, or a mixed material which is an alloy, compound, or non-equilibrium alloy mainly composed of the first component, the third component may consist of Ni, and the metallic material may be an Fe-containing alloy. Alternatively, the first component may consist of Mg, the metallic body may consist of only the first component, or a mixed material which is an alloy, compound, or non-equilibrium alloy mainly composed of the first component, the third component may consist of Cu, and the metallic material may be a Ti-containing alloy.

[0031] Furthermore, in these cases, the metal body is an alloy containing Mg, Zn, and Y or Zr, or an alloy containing Mg, Al, and Zn, and the metal material is Fe 100-x Ni x (30 ≤ x ≤ 70, values ​​are in at%), or Ti 100-y Cu y(30≦y≦70, values ​​are at%) may be included. In this case, there may be an Fe alloy or Ti alloy bonded to the metal material so as to sandwich the metal material between the metal body and the metal material, and there may be a metal or alloy having a different composition from the metal material, containing at least one of Mg, Zn, Y, Zr, and Al, bonded to the metal body so as to sandwich the metal material between the metal body and the metal material. In this case, the Fe alloy is preferably carbon steel or stainless steel. Furthermore, the Ti alloy is preferably Ti and at least one of Al, V, Nb, Ni, Cr, and Sn.

[0032] The composite member according to the present invention can be suitably manufactured by the method for manufacturing a joint between solid metals according to the present invention or by the method for manufacturing a joint according to the present invention. [Effects of the Invention]

[0033] According to the present invention, it is possible to provide a method for manufacturing a jointed body of solid metals and a composite member that can increase the bonding strength at the joint surface. [Brief explanation of the drawing]

[0034] [Figure 1] The present invention relates to a method for manufacturing a bonded body of solid metals according to an embodiment of the present invention, and shows the following after diffusion bonding of Ti and Ti100-xCux: (a) Upper figure: SEM (scanning electron microscope) image of the vicinity of the bonding interface when x=65 and lower figure: EDX (energy dispersive X-ray) analysis results along the line in the SEM image, (b) SEM image of the vicinity of the bonding interface when x=33 and 50, and (c) XRD spectra of the surface of the Ti-Cu layer when x=33, 50, and 65. [Figure 2]The images show: (a) an SEM image near the bonding interface between Ti100-xCux (x=50) and Mg, and the EDX analysis results along the line in the SEM image, obtained by the method for manufacturing a bonded body of solid metals according to an embodiment of the present invention; (b) an enlarged SEM image of the solidification microstructure in the Mg-Cu phase in the SEM image of (a), and the Cu-Mg binary equilibrium phase diagram; and (c) an SEM image of the boundary region between the Ti2Cu / Mg-Cu phase and the α-Ti / Mg-Cu phase in the SEM image of (a), and the EDX line analysis results along the line in the SEM image. [Figure 3] Figure 2 is an explanatory diagram showing the reaction flow in the method for manufacturing a bonded metal solid according to an embodiment of the present invention. [Figure 4] The graph shows the change in the thickness of the Mg-Cu phase layer (Mg-Cu layer) at the bonding interface between Ti100-xCux (x=33, 50, 65) and Mg, with respect to bonding pressure, for a bonded body obtained by the manufacturing method of a bonded body of solid metals according to an embodiment of the present invention. The inset figures show: x=33, an SEM image of the vicinity of the bonding interface when the bonding pressure is 1 MPa, an SEM image of the vicinity of the bonding interface when the bonding pressure is 20 MPa, and the appearance of the side surface after cooling when the bonding pressure is 20 MPa. [Figure 5] The images show (a) an SEM image of the joint between Ti100-xCux (x=65) and Mg, obtained when the joining pressure was 20 MPa, in a method for manufacturing a joint of solid metals according to an embodiment of the present invention, (b) the EDX analysis result along the line in the SEM image of (a), (c) an enlarged SEM image of the area of ​​(c) in the SEM image of (a), and (d) an enlarged SEM image of the area of ​​(d) in the SEM image of (a). [Figure 6] The following are diagrams showing (a) a plan view of the shape of a test specimen for a tensile test of a joint made of Ti100-xCux and Mg, obtained when the joining pressure was 0.2 MPa or 20 MPa, according to an embodiment of the present invention for manufacturing a joint made of solid metals, and (b) a graph showing the results of the tensile test when x = 33, 40, 50, and 65. [Figure 7](a) A load-displacement curve measured by an ultramicrohardness tester and an inset: micrograph of the indentation mark in the co-continuous microstructure (labeled "Ti / Mg composite" in the figure) near the bonding interface between Ti100-xCux (x=50) and Mg in a bond obtained when the bonding pressure was 20 MPa in a method for manufacturing a bond between solid metals according to an embodiment of the present invention, and (b) a graph showing the indentation hardness Hit obtained from (a). [Figure 8] The following shows the procedure for a bonding experiment between Fe100-xNix (x=50) and KUMADAI magnesium alloy in a method for manufacturing a bonded metal solid body according to an embodiment of the present invention: (a) the first step of bonding S45C and Fe100-xNix, (b) the second step of bonding Fe100-xNix and KUMADAI magnesium alloy, and (c) the tensile test method. [Figure 9] Figure 8(a) shows the area near the bonding interface between S45C and Fe100-xNix after the first stage, (a) an SEM image of the bonding interface, (b) an enlarged SEM image of a part of (a), (c) the surface analysis results of Fe using EDX in the area of ​​(b), (d) the surface analysis results of Ni, (e) the surface analysis results of Mn, and (f) the line analysis results of EDX along the line in the SEM image of (a). [Figure 10] Figure 8(b) shows the (a) external appearance of the Fe100-xNix and KUMADAI magnesium alloy bond after the second stage, (b) an SEM image of the area near the bonding interface, and (c) an enlarged SEM image of a part of (b). [Figure 11] Figure 10(c) shows the surface analysis results for (a) Mg, (b) Fe, (c) Zn, (d) Y, and (e) Ni in the area of ​​EDX. [Figure 12] Figure 8(c) shows (a) an SEM image of the KUMADAI magnesium alloy side and (b) an SEM image of the Fe100-xNix side of the fractured sample piece in the tensile test. [Modes for carrying out the invention]

[0035] Embodiments of the present invention will be described below with reference to the drawings and examples. The method for manufacturing a jointed metal body according to an embodiment of the present invention involves joining a solid metal body and a solid metal material as follows.

[0036] Specifically, first, a solid metal body and a solid metallic material are prepared. The solid metal body contains a first component and consists of either the first component alone, or a mixed mixture that is an alloy, compound, or non-equilibrium alloy with the first component as the main component. The solid metallic material consists of a mixed mixture that is a compound, alloy, or non-equilibrium alloy containing both a second and a third component simultaneously. The second and third components have positive and negative heats of mixing relative to the first component, respectively. Furthermore, the third component undergoes a eutectic reaction with the first component at a predetermined temperature.

[0037] Specifically, the first component consists of one or more of Li, Mg, Ca, Cu, Zn, Ag, Pb, Bi, and rare earth metal elements. The second component consists of one or more of Ti, Zr, Hf, Nb, Ta, Cr, V, Mo, W, Fe, Co, Ni, C, Si, Ge, and Sn. The third component consists of one or more of Li, Mg, Ca, Mn, Fe, Co, Ni, Cu, Ti, Zr, Hf, Nb, Ta, Cr, Mo, and W.

[0038] Next, the metal body and the metal material are brought into contact, and a predetermined pressure is applied between the metal body and the metal material while performing heat treatment at a predetermined temperature for a predetermined time. At this time, the predetermined temperature for the heat treatment is lower than the melting points of the metal body and the metal material, and higher than the temperature at which the first component and the third component react eutectically to form an alloy liquid, i.e., the melting point or liquidus temperature of that alloy liquid.

[0039] Through heat treatment, the third component mutually diffuses from the metal material into the metal body, and the first component mutually diffuses from the metal body into the metal material. Simultaneously, in the region where the first and third components mutually diffuse, the first and third components undergo a eutectic reaction, producing an alloy liquid containing the first and third components. The second component does not diffuse into the metal body. As a result, in the region of the metal material where the first and third components mutually diffuse, a co-continuous structure can be formed in which the parts containing the first and third components and the parts containing the second component are finely intertwined on the order of nanometers or micrometers.

[0040] Furthermore, the resulting alloying liquid contains the first and third components, but not the second component. The alloying liquid may also contain components other than the second component, in addition to the first and third components. For example, the alloying liquid may include those that, upon solidification, form an intermetallic compound in which the first and third components are bonded together.

[0041] If this alloy liquid solidifies as is, it becomes brittle, reducing the bonding strength at the joint between the metal body and the metal material. Therefore, by applying a predetermined pressure while performing heat treatment, the resulting alloy liquid can be discharged to the outside, preventing a decrease in bonding strength at the joint. Specifically, the alloy liquid is discharged from the area where the third component on the metal body side has diffused within the region where the first component and the third component have mutually diffused, that is, from the boundary between the region on the metal body side that does not contain the third component and the region that contains the third component, to the boundary (joint surface) between the metal body and the metal material. To perform this bonding more effectively, the thickness of the metal material is preferably 500 μm or less, more preferably 200 μm or less, and most preferably 100 μm or less. There is no particular limit to the lower limit of the thickness, but it is 0.2 nm or more as it is possible to manufacture the metal material. Note that the alloy liquid may adhere to the area around the joint where the metal body and metal material are joined after discharge.

[0042] Thus, the method for manufacturing a joint of solid metals according to the embodiment of the present invention makes it possible to join solid metals that are normally difficult to join by utilizing interdiffusion between the solids. This makes it possible to manufacture a joint, which is a composite member according to the embodiment of the present invention. Furthermore, the method for manufacturing a joint of solid metals according to the embodiment of the present invention can increase the joint strength compared to when no predetermined pressure is applied. In addition, ductility can be increased by discharging the alloy liquid, which becomes brittle when solidified, to the outside.

[0043] Furthermore, in the method for manufacturing a bonded metal solid body according to the embodiment of the present invention, the contact area between the metal body and the metal material melts due to a eutectic reaction between the first component and the third component, allowing the interdiffusion between the first component and the third component to occur in the liquid phase. This allows the interdiffusion between the first component and the third component to proceed more rapidly, and the bonding time can be shortened compared to solid-phase diffusion.

[0044] Furthermore, the method for manufacturing a bonded metal solid according to the embodiment of the present invention does not require heating above the melting point of the metal body or metal material by utilizing interdiffusion due to eutectic reaction between the solids. Therefore, compared to cases where the metal is heated above its melting point, the heating temperature required for joining can be lowered, and the time and cost required for heating can be reduced.

[0045] Furthermore, in the embodiment of the present invention, a method for manufacturing a joint of two solid metals can be used to join two solid metals that cannot be directly joined. This method involves preparing a metal body for one solid metal and a metal material bonded to the surface of the other solid metal, and then joining the metal body and the metal material using the method for manufacturing a joint of two solid metals according to the present invention. Alternatively, after joining the metal body (one solid metal) and the metal material, the other solid metal may be joined to the metal material. [Examples]

[0046] Using the method for manufacturing a bonded metal solid according to an embodiment of the present invention, Ti is provided on the surface of Ti 100-x Cu x Bonding experiments were conducted with Mg. In this experiment, the first component was Mg, the second component was Ti, and the third component was Cu. The experiment used pure Mg (99.9 mass%) and pure Ti (99.9 mass%) with a diameter of 15 mm and a thickness of 15 mm, as well as Ti with a diameter of 10 mm and a thickness of 1.2 mm. 100-x Cu x [x=33~65, values ​​are at% (same for the following)] (Ti: 99.9 mass%, Cu: 99.99 mass%) were prepared. 100-x Cu x This product is manufactured by arc melting Ti and Cu in a high-purity Ar atmosphere, casting them at an angle into a round copper mold, and then machining them.

[0047] In the experiment, as the first stage, one surface of Ti and Ti were subjected to a multi-furnace argon flow. 100-x Cu xWith one surface of the two materials butted together under a pressure of 5 MPa, high-frequency heating was performed at 1073 K for 60 minutes, and Ti and Ti 100-x Cu x The materials were diffusion-bonded. Subsequently, in the second step, in an argon flow multi-furnace, the materials were bonded using the method for manufacturing a bonded metal solid body according to the embodiment of the present invention, Ti 100-x Cu x The other surface of Ti and the other surface of Mg are butted together at a predetermined pressure (joining pressure), and then heat-treated at a predetermined temperature (heat treatment temperature). 100-x Cu x It was joined to Mg.

[0048] First, the first stage Ti and Ti 100-x Cu x SEM (scanning electron microscope) observation, EDX (energy-dispersive X-ray) analysis, and XRD analysis were performed on the vicinity of the bonding interface after diffusion bonding. A Zeiss "Ultra55" scanning electron microscope was used, and a Bruker "XFlash" was used for EDX analysis (the same applies below). Figure 1(a) shows the SEM image and EDX analysis results of the vicinity of the bonding interface when x=65, Figure 1(b) shows the SEM images when x=33 and 50, and Figure 1(c) shows the XRD spectra of the surface of the Ti-Cu layer when x=33, 50, and 65.

[0049] As shown in Figure 1(a), when x=65, it was confirmed that various compounds such as Ti2Cu, TiCu, and Ti3Cu4 were formed within the Ti-Cu layer. Furthermore, as shown in Figure 1(b), when x=50, it was confirmed that only Ti2Cu was formed within the Ti-Cu layer, and when x=33, it was confirmed that only Ti2Cu and TiCu were formed within the Ti-Cu layer. In addition, no voids or bonding defects were observed at the bonding interface, confirming that sufficient diffusion bonding was achieved. Furthermore, as shown in Figure 1(c), it was confirmed that Ti2Cu was formed on the surface of the Ti-Cu layer when x=33, TiCu when x=50, and TiCu4 and Ti2Cu3 when x=65. Note that all of these phases are brittle intermetallic compounds.

[0050] Next, the second stage Ti 100-x Cu x SEM observation and EDX analysis were performed near the bonding interface between TiCu and Mg. Figure 2(a) shows the SEM image and EDX analysis results near the bonding interface when x=50, the heat treatment temperature was 803 K, the holding time was 15 minutes, and the bonding pressure was 5 MPa. As shown in Figure 2(a), it was confirmed that the TiCu layer, Ti2Cu / Mg-Cu phase, α-Ti / Mg-Cu phase, Mg-Cu phase, and Mg layer were formed in layers from left to right. Figure 2(b) shows a magnified SEM image of the solidification microstructure, including primary crystals such as dendrites in the Mg-Cu phase confirmed in Figure 2(a). Figure 2(c) shows a magnified SEM image and EDX radiation analysis results of the boundary region between the Ti2Cu / Mg-Cu phase and the α-Ti / Mg-Cu phase confirmed in Figure 2(a).

[0051] EDX compositional analysis of the solidified microstructure containing the primary crystal shown in Figure 2(b) revealed that the fine two-phase microstructure contains 83 at% Mg and 17 at% Cu, while the coarse phase contains 99.7 at% Mg and 0.3 at% Cu. These compositions can be confirmed from the Cu-Mg binary equilibrium phase diagram shown in the figure (Alloy Phase Diagram Database (ASM), Copper-Magnesium Binary Phase Diagram (2008 Miettien J.), 2024, https: / / matdata.asminternational.org / apd / index.aspx). In other words, when Mg and Cu are joined by butt joint at 803 K, a eutectic reaction occurs at their interface, generating a Mg-Cu molten material. Subsequently, as the temperature decreases, this molten material solidifies, first forming a primary crystal of α-Mg, followed by the formation of a eutectic crystal of Mg2Cu and α-Mg. Applying this to the observations shown in Figure 2(b), Ti 50 Cu 50 It is thought that eutectic melting is also occurring at the junction interface between the eutectic and Mg.

[0052] The results shown in Figure 2 summarize the reaction in the second stage, which is shown in Figure 3. As shown in Figure 3, first, Ti-Cu (Ti-Cu interlayer) and Mg (α-Mg) are brought together at a predetermined pressure [step (i)]. When heat treatment is performed while maintaining this state, solid-phase diffusion occurs at the contact interface, and Cu and Mg mutually diffuse. As this mutual diffusion progresses, a eutectic reaction occurs at and near the contact interface, and a melt of Mg-Cu (molten material; Mg-Cu melt) is generated [step (ii)]. Furthermore, Cu from Ti-Cu dissolves into the generated melt, and the Mg-Cu melt diffuses toward the Ti-Cu side. At this time, the Ti-containing phases connect in the area where Mg has diffused from within the Ti-Cu, and the Mg-Cu melt occupies the space between the Ti-containing phases while maintaining continuity. In this way, the Mg-Cu melt penetrates between the Ti-containing phases and self-assembles a continuous structure [step (iii)]. When the Mg-Cu melt is cooled and solidified, a co-continuous microstructure in which the Ti-containing phase and the Mg-Cu phase are intertwined on the order of nanometers or micrometers, and a layer consisting of the Mg-Cu phase is formed [step (iv)].

[0053] As shown in Figure 2, the bonding interface still contains brittle phases such as Mg2Cu, which can lead to a decrease in bonding strength. Therefore, the bonding pressure during the heat treatment in the second stage was changed to Ti 100-x Cu x Bonding experiments were conducted between Cu and Mg. In the experiments, for each of the cases x = 33, 50, and 65, the heat treatment temperature in the second stage was set to 813 K, the holding time to 30 minutes, and the bonding pressure was set to 0 MPa or 1 MPa, 5 MPa, 10 MPa, and 20 MPa. After bonding under each condition, the thickness of the layer consisting of the Mg-Cu phase was measured.

[0054] Figure 4 shows the change in the thickness of the Mg-Cu phase layer (Mg-Cu layer) with respect to the bonding pressure. In addition, insets of Figure 4 show SEM images of the vicinity of the bonding interface at x=33 and a bonding pressure of 1 MPa, an SEM image of the vicinity of the bonding interface at a bonding pressure of 20 MPa, and the appearance of the side surface after cooling at a bonding pressure of 20 MPa.

[0055] As shown in Figure 4 and the inset, increasing the joining pressure thins the Mg-Cu layer. At 10 MPa, almost no Mg-Cu layer remains, and at 20 MPa, none remains at all. Furthermore, as shown in the inset of Figure 4, after cooling, it was confirmed that the Mg-Cu molten material adheres to and solidifies around the joined body. These results suggest that by applying a predetermined pressure during heat treatment, the alloy liquid consisting of Mg-Cu molten material can be discharged from the joining interface, and increasing the joining pressure increases the amount of Mg-Cu molten material discharged. In addition, this prevents the formation of brittle phases such as Mg2Cu after cooling, thus preventing a decrease in joint strength at the joint surface. It was also confirmed that in layers where the Ti-containing phase and the Mg-Cu phase are intertwined, the Mg-Cu phase remains regardless of the pressure.

[0056] Next, when x=65, the heat treatment temperature in the second stage is 773 K, the holding time is 5 minutes, and the bonding pressure is 20 MPa, Ti 100-x Cu x Bonding experiments were conducted with Mg. SEM images and EDX analysis results of the area near the bonding interface after bonding are shown in Figures 5(a) and (b), respectively. SEM images of the areas shown in (c) and (d) in Figure 5(a) are shown in Figures 5(c) and (d), respectively, with magnification.

[0057] As shown in Figures 5(a) and (b), Ti between Ti and Mg 100-x Cu xIt was confirmed that the entire layer was dealloyed, and that Ti and Mg were joined only by a co-continuous microstructure consisting of an α-Ti / Mg-Cu phase without a brittle phase. Furthermore, as shown in Figure 5(c), no cracks indicating metallic bonding were observed between the pure Ti and the co-continuous microstructure, and as shown in Figure 5(d), no layer consisting of the Mg-Cu phase was observed between the co-continuous microstructure and Mg.

[0058] Next, for x = 33, 40, 50, and 65, the heat treatment temperature in the second stage is set to 773 K to 813 K, the holding time to 5 to 30 minutes, and the predetermined pressure to 0.2 MPa or 20 MPa, Ti 100-x Cu x A bond was formed between the metal and Mg. Tensile tests were performed on each bonded structure. For the tensile tests, test specimens were cut into the shape shown in Figure 6(a) using a wire electrical discharge machine. A Shimadzu AG50VF was used to set the strain rate to 5.0 × 10⁻⁶. -4 (s -1 A tensile test was performed on each sample (the same procedure was followed below). Three tensile tests were conducted on each sample, and the average value was used as the test result. The results of the tensile tests are shown in Figure 6(b).

[0059] As shown in Figure 6(b), at x=40 (0.2 MPa), x=50 (0.2 MPa), and x=65 (0.2 MPa), the fracture strength was confirmed to be 39.8 MPa to 58.7 MPa (indicated as "Interfacial fracture" in the figure). It was also confirmed that the fracture location was the layer consisting of the Mg-Cu phase near the bonding interface or its interface. In contrast, at x=33 (20 MPa), x=50 (20 MPa), and x=65 (20 MPa), the fracture strength was 83.3 MPa to 90.3 MPa, confirming that the fracture occurred within the Mg (indicated as "Mg base metal fracture" in the figure). From these results, it can be said that increasing the bonding pressure can increase the bonding strength at the bonding surface. Furthermore, it was confirmed that this bonding strength is higher than the strength of Mg.

[0060] Next, for x=50, the hardness of the co-continuous microstructure consisting of Ti, Mg, and α-Ti / Mg-Cu phases of the bonded material, which was bonded with a heat treatment temperature of 803 K, a holding time of 15 minutes, and a predetermined pressure of 20 MPa in the second stage, was measured using an ultra-micro hardness tester (ENT-1100b, manufactured by Elionix Co., Ltd.). In the measurement, the maximum load was set to 200 mN, and the spacing between each indentation was made larger than 10 μm to avoid the effects of work hardening. In addition, five measurements were taken for each measurement target, and the average value was calculated.

[0061] Figure 7(a) shows the load-displacement curves obtained by an ultramicrohardness tester for co-continuous microstructures consisting of Ti, Mg, and α-Ti / Mg-Cu phases, and the inset shows a micrograph of the indentation mark for the co-continuous microstructure (labeled "Ti / Mg composite" in the figure). As shown in Figure 7(a), the load-displacement curves were smooth for all structures, confirming elastoplastic behavior. Furthermore, as shown in the inset, no cracks were observed from the apex of the indentation mark, confirming that the co-continuous microstructure is non-brittle.

[0062] Based on the measurement results using an ultramicro hardness tester, the indentation hardness H it The indentation hardness H of the co-continuous microstructure is calculated and shown in Figure 7(b). As shown in Figure 7(b), it The indentation hardness H of Ti and Mg it It was confirmed to be located between. According to ISO 14577, H it Since there is a correlation between this and Vickers hardness (HV), it is thought that the co-continuous microstructure exhibits strength intermediate between that of Ti and Mg. [Examples]

[0063] Using the method for manufacturing a joint between solid metals according to an embodiment of the present invention, Fe is provided on the surface of carbon steel S45C (manufactured by Asano Steel Co., Ltd.) 100-x Ni xBonding experiments were conducted between (x=50) and KUMADAI magnesium alloy (Mg-Zn-Y alloy; manufactured by Fuji Light Metal Co., Ltd.). In this case, the first component is Mg, the second component is Fe, and the third component is Ni. In the experiment, S45C and KUMADAI magnesium alloy with a diameter of 15 mm and a thickness of 15 mm, as well as Fe with a thickness of 0.1 mm, were bonded. 100-x Ni x I prepared Fe 100-x Ni x It is manufactured by arc melting Fe and Ni, casting them at an angle into a round copper mold, and then rolling them.

[0064] In the experiment, as the first step, as shown in Figure 8(a), one surface of S45C and Fe 100-x Ni x One surface of the material is butted against the other at a pressure of 25 MPa, and then hot-pressed at 800 °C (1073 K) for 1 hour, resulting in a mixture of S45C and Fe 100-x Ni x The two were joined together. Subsequently, as the second step, as shown in Figure 8(b), the Fe was joined together using the method for manufacturing a joint of solid metals according to the embodiment of the present invention. 100-x Ni x The other surface of the material and the other surface of the KUMADAI magnesium alloy are butted together with a joining pressure of 25 MPa, and then heat-treated at 510 °C (783 K) for 30 minutes, Fe 100-x Ni x The KUMADAI magnesium alloy was joined to the material. Subsequently, as shown in Figure 8(c), a tensile test was performed to examine the joint strength.

[0065] First, the first stage involves S45C and Fe 100-x Ni x SEM observation and EDX analysis were performed near the bonding interface after hot pressing. SEM images of the bonding interface are shown in Figures 9(a) and (b), the EDX surface analysis results are shown in Figures 9(c) to (e), and the line analysis results are shown in Figure 9(f). As shown in Figure 9, S45C and Fe 100-x Ni x The two materials were joined directly, and no intermetallic compounds were found near the bonding interface.

[0066] Next, the second stage Fe 100-x Ni x SEM observation and EDX analysis were performed near the bonding interface between the material and the KUMADAI magnesium alloy. The appearance of the bonded body after bonding (after cooling) is shown in Figure 10(a), and SEM images of the area near the bonding interface are shown in Figures 10(b) and (c). The EDX analysis results are shown in Figures 11(a) to (e). As shown in Figures 10(b), (c) and 11, it was confirmed that a fine composite structure (Reaction layer in the figures) consisting of the Fe-Mg phase was formed at the bonding interface. Furthermore, the formation of intermetallic compounds such as the Mg-Ni phase was not confirmed. In addition, as shown in Figure 10(a), it was confirmed that after cooling, the Mg-Ni melt adhered to and solidified around the bonded metal member.

[0067] These results suggest that applying pressure during heat treatment can expel the alloy liquid, consisting of Mg-Ni molten metal, from the joint interface. Furthermore, this prevents the formation of brittle phases such as Mg2Ni after cooling, thus preventing a decrease in joint strength at the joint surface.

[0068] Next, a tensile test was performed on the bonded joint. For the tensile test, a specimen was cut into the shape shown in Figure 6(a) and the test was performed three times. The tensile strengths obtained were 193 MPa, 160.4 MPa, and 142 MPa, with an average value of 165 MPa. An example of an SEM image of the specimen at the fracture site in the tensile test is shown in Figures 12(a) and (b). As shown in Figure 12, the tensile test confirmed that the fracture occurred within the microcomposite structure consisting of the Fe-Mg phase formed at the bonding interface. [Examples]

[0069] Using the method for manufacturing a bonded metal solid according to an embodiment of the present invention, Ti 100-x Cu x A bonding experiment was conducted between (x=50, 65) and the magnesium alloy ZK60 (Mg-Zn-Zr alloy). In this case, the first component is Mg, the second component is Ti, and the third component is Cu.100-x Cu x The surface of the material and the surface of the ZK60 are butted together with a bonding pressure of 20 MPa, and then heat-treated at 540 °C (813 K) for 5 minutes. 100-x Cu x The ZK60 was joined to it.

[0070] Tensile tests were performed on the joined material after bonding, and the tensile strength was found to be 240 MPa. Fracture was confirmed at the layer composed of the Mg-Cu phase formed at the bonding interface and at its boundary. These results suggest that applying pressure during heat treatment allows the alloy liquid composed of Mg-Cu molten material to be expelled from the bonding interface, preventing a decrease in bonding strength at the bonding surface.

[0071] Furthermore, the ZK60 Ti is applied to the bonded body after bonding. 100-x Cu x On the opposite side of the surface, a magnesium alloy AZ31 (Mg-Al-Zn alloy) was bonded by diffusion bonding. This allowed for direct bonding of Ti, which could not be bonded directly. 100-x Cu x We were able to connect AZ31 and ZK60.

Claims

1. A method for manufacturing a bonded metal solid, characterized by bringing a solid metal body containing a first component into contact with a solid metal material consisting of a compound, alloy, or non-equilibrium alloy containing a second component and a third component, each having positive and negative mixing heats with respect to the first component, respectively, and applying a predetermined pressure between the metal body and the metal material while performing heat treatment at a predetermined temperature for a predetermined time, thereby causing the first component and the third component to interdiffuse, and discharging an alloy liquid containing the first component and the third component that has been generated in the region where the first component and the third component have interdiffused.

2. The method for manufacturing a bonded metal solid according to claim 1, characterized in that the alloy liquid is formed by a eutectic reaction between the first component and the third component in a region where the first component and the third component have interdiffused.

3. The alloy liquid has a melting point lower than the melting point of the metal body. The predetermined temperature is lower than the melting point of the metal body and the metal material, and higher than the melting point or liquidus temperature of the alloy liquid. A method for manufacturing a bonded body of solid metals as described in claim 1.

4. The method for producing a metal solid joint according to claim 1, characterized in that the alloy liquid contains a material that, when solidified, forms an intermetallic compound in which the first component and the third component are bonded together.

5. The method for manufacturing a bonded metal solid according to claim 1, characterized in that the alloy liquid does not contain the second component.

6. The method for manufacturing a bonded metal solid according to claim 1, characterized in that the predetermined pressure is 10 MPa or more.

7. The first component consists of one or more of Li, Mg, Ca, Cu, Zn, Ag, Pb, Bi, and rare earth metal elements. The metal body consists of only the first component, or a mixed body which is an alloy, compound, or non-equilibrium alloy mainly composed of the first component. The second component consists of one or more of Ti, Zr, Hf, Nb, Ta, Cr, V, Mo, W, Fe, Co, Ni, C, Si, Ge, and Sn. The third component consists of one or more of Li, Mg, Ca, Mn, Fe, Co, Ni, Cu, Ti, Zr, Hf, Nb, Ta, Cr, Mo, and W. The aforementioned metallic material consists of a mixed alloy, compound, or non-equilibrium alloy containing both the second and third components simultaneously. A method for manufacturing a bonded body of solid metals according to any one of claims 1 to 6.

8. The first component consists of Mg, The metal body consists of only the first component, or a mixed body which is an alloy, compound, or non-equilibrium alloy mainly composed of the first component. The aforementioned third component consists of Ni, The aforementioned metal material is an Fe-containing alloy. A method for manufacturing a bonded body of solid metals according to any one of claims 1 to 6.

9. The first component consists of Mg, The metal body consists of only the first component, or a mixed body which is an alloy, compound, or non-equilibrium alloy mainly composed of the first component. The third component is made of Cu, The aforementioned metal material is a Ti-containing alloy. A method for manufacturing a bonded body of solid metals according to any one of claims 1 to 6.

10. A method for manufacturing a joined body, characterized by bringing a solid metal body containing Mg or an Mg alloy into contact with a solid metal material containing an alloy of Ni and Fe, or an alloy of Ti and Cu, and applying pressure between the metal body and the metal material while heating the metal body and the metal material to join them together.

11. The aforementioned metal body is an alloy containing Mg, Zn, and Y or Zr, or an alloy containing Mg, Al, and Zn. The aforementioned metal material is Fe １００－ｘ Ni ｘ (30 ≤ x ≤ 70, values ​​are at%), or Ti １００－ｙ Cu ｙ (30 ≤ y ≤ 70, the value is at%) A method for manufacturing a joint according to claim 10, characterized by the present invention.

12. The process involves joining an Fe alloy or Ti alloy to the metal material such that the metal material is sandwiched between the metal body. Furthermore / or, The process involves joining a metal or alloy to the metal body, with the metal body sandwiched between the aforementioned metal material, and the metal body containing at least one of Mg, Zn, Y, Zr, and Al, having a different composition from the aforementioned metal material. A method for manufacturing a joint according to claim 11, characterized by the present invention.

13. The method for manufacturing a joint according to claim 12, characterized in that the Fe alloy is carbon steel or stainless steel.

14. The method for manufacturing a bonded body according to claim 12, characterized in that the Ti alloy comprises Ti and at least one of Al, V, Nb, Ni, Cr, and Sn.

15. A solid metal body containing the first component, A portion having the first component and a third component having a negative heat of mixing with respect to the first component, and a portion having a second component having a positive heat of mixing with respect to the first component, are intertwined on a nanometer or micrometer order, forming a co-continuous structure. The aforementioned co-continuous structure is bonded to the surface of the metal body. Characteristic composite material.

16. The present invention comprises a solid metallic material consisting of a compound, alloy, or non-equilibrium alloy containing both the second and third components, The aforementioned metal material is bonded to the aforementioned metal body with the aforementioned co-continuous structure in between. The composite member according to claim 15, characterized by its features.

17. The composite material according to claim 15, characterized in that the third component reacts with the first component at a temperature lower than the melting point of the metal body through a eutectic reaction.

18. The first component consists of one or more of Li, Mg, Ca, Cu, Zn, Ag, Pb, Bi, and rare earth metal elements. The metal body consists of only the first component, or a mixed body which is an alloy, compound, or non-equilibrium alloy mainly composed of the first component. The second component consists of one or more of Ti, Zr, Hf, Nb, Ta, Cr, V, Mo, W, Fe, Co, Ni, C, Si, Ge, and Sn. The third component consists of one or more of Li, Mg, Ca, Mn, Fe, Co, Ni, Cu, Ti, Zr, Hf, Nb, Ta, Cr, Mo, and W. The composite member according to claim 15, characterized by its features.

19. The first component consists of Mg, The metal body consists of only the first component, or a mixed body which is an alloy, compound, or non-equilibrium alloy mainly composed of the first component. The aforementioned third component consists of Ni, The aforementioned metal material is an Fe-containing alloy. The composite member according to claim 16, characterized by its features.

20. The first component consists of Mg, The metal body consists of only the first component, or a mixed body which is an alloy, compound, or non-equilibrium alloy mainly composed of the first component. The third component is made of Cu, The aforementioned metal material is a Ti-containing alloy. The composite member according to claim 16, characterized by its features.

21. The aforementioned metal body is an alloy containing Mg, Zn, and Y or Zr, or an alloy containing Mg, Al, and Zn. The aforementioned metal material is Fe １００－ｘ Ni ｘ (30 ≤ x ≤ 70, values ​​are at%), or Ti １００－ｙ Cu ｙ (30 ≤ y ≤ 70, the value is at%) The composite member according to claim 19 or 20, characterized by the features described above.

22. The metal body has an Fe alloy or Ti alloy bonded to it, with the metal material sandwiched between them. Furthermore / or, The metal body is joined to the metal body so as to sandwich the metal body between the metal material, and the metal or alloy having a different composition from the metal material, containing at least one of Mg, Zn, Y, Zr, and Al. The composite member as described in claim 21, characterized by its features.

23. The composite member according to claim 22, characterized in that the Fe alloy is carbon steel or stainless steel.

24. The composite member according to claim 22, characterized in that the Ti alloy comprises Ti and at least one of Al, V, Nb, Ni, Cr, and Sn.

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