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JP-7855215-B2 - Joint and its manufacturing method

JP7855215B2JP 7855215 B2JP7855215 B2JP 7855215B2JP-7855215-B2

Inventors

  • 田中 努
  • 片桐 一彰
  • 平田 智丈
  • 中本 貴之
  • 菅原 貴広
  • 四宮 徳章
  • 三木 隆生
  • 内田 壮平
  • 根津 将之

Assignees

  • 地方独立行政法人大阪産業技術研究所

Dates

Publication Date
20260508
Application Date
20211228

Claims (5)

  1. A first member is made of a first material selected from the group including metallic materials, polymer materials, ceramic materials, and composite materials thereof, and has protrusions on its front surface. A second member is joined to the first member on the front side of the first member and is made of a second material which includes at least a metal material. Equipped with, A method for manufacturing a joint, wherein the joint portion of the second member that joins with the first member is composed of a fine-grained structure that satisfies at least one of the following conditions: the maximum grain size is 100 μm or less and the average grain size is 30 μm or less, The process includes a protrusion formation step in which the protrusion of the first member is formed by an additive manufacturing method, A joining step of joining the second member to the first member Includes , A manufacturing method comprising the joining process, wherein the portion of the second member facing the first member is made to flow in a solid state by friction stir processing or friction pressure welding, thereby forming the joint portion composed of a non-molten solidified structure .
  2. In the manufacturing method described in claim 1 , A manufacturing method comprising a processing step, which is performed after the projection forming step and before the joining step, for removing deposits from the tip of the projection.
  3. In the manufacturing method described in claim 1 or 2, A manufacturing method comprising the following steps: inserting a joining tool having screw threads into the second member, and performing the friction stir machining.
  4. In the manufacturing method described in any one of claims 1 to 3, A manufacturing method comprising the joining step of applying a rotational force to the second member in a direction parallel or perpendicular to the surface of the first member, thereby causing the portion of the second member facing the first member to flow in a solid state.
  5. In the manufacturing method according to any one of claims 1 to 4, The projection has a portion with an increased cross-sectional area, such that as it moves away from the surface of the first member, the horizontal cross-sectional area when cut in a horizontal direction parallel to the surface of the first member increases. A manufacturing method wherein 50% or more of the volume of the space on the back side of the enlarged cross-section is filled with the second material that constitutes the joint.

Description

This invention relates to a jointed body in which multiple members are joined together, and a method for manufacturing the same. Patent Document 1 discloses a dissimilar material joint (jointed body) comprising a first member and a second member having a larger coefficient of thermal expansion than the first member and joined to the first member, wherein the first member has a projection protruding from a part of its surface, and the second member is fitted onto the projection at the joint surface between the first and second members. Japanese Patent Publication No. 2019-69452 This is a plan view showing the first member of the joint according to the first embodiment from the front side.This is a vertical cross-sectional view of the joint.This is a schematic diagram showing the joining process in the manufacturing method of a joined body.This is a diagram corresponding to Figure 1, relating to a first modified example of the first embodiment.This is a diagram corresponding to Figure 2, relating to a second modified example of the first embodiment.This is a diagram corresponding to Figure 2, relating to a third modified example of the first embodiment.This graph shows the results of tensile tests on the joints according to Examples 1 and 2 and Comparative Examples 1 and 2.This graph shows the results of the tensile test of the joints according to Examples 3 and 4.This is an SEM image of the cross-section of the joint according to Example 1.This is an SEM image of the cross-section of the joint according to Comparative Example 2.This is an SEM image of the cross-section of the joint according to Example 3.This is an SEM image of the cross-section of the joint according to Example 4.Figure 9 shows an image obtained by EBSD analysis of a SEM image.Figure 10 shows an image obtained by EBSD analysis of a SEM image.Figure 13 is a graph showing the grain size distribution in the image shown.Figure 14 is a graph showing the grain size distribution in the image shown.This image shows the maximum stress distribution per unit area in the joint model according to Example 10.This image shows the maximum stress distribution per unit area in the joint model according to Example 11. The embodiments of the present invention will be described in detail below with reference to the drawings. The following description of preferred embodiments is illustrative in nature and is not intended to limit the present invention, its applications, or its uses. (First Embodiment) —Structure of the joint— As shown in Figures 1 and 2, the jointed body 1 according to the first embodiment comprises a first member 10 made of a first material which is a metal material, and a second member 20 made of a second material which is a metal material, which is joined to the first member 10 on the front side of the first member 10. Specifically, the first member 10 has a plurality of protrusions 11, 11, ... on its front surface. Each protrusion 11 is circular in plan view, as shown in Figure 1, and its horizontal cross-section, cut along a direction parallel to the first member surface 12, is also circular. Furthermore, each protrusion 11 is formed such that its diameter increases proportionally to its distance from the first member surface 12, as shown in Figure 2. That is, each protrusion 11 is composed of a cross-sectional area increasing portion 11a, where the horizontal cross-sectional area increases with distance from the first member surface 12. Note that the materials used to constitute the protrusions 11 and the parts of the first member 10 other than the protrusions 11 may differ. As shown in Figure 2, the circumferential surface of the increased cross-section portion 11a, when viewed in a vertical cross-section perpendicular to the surface 12 of the first member, has a tangent line that intersects the surface 12 of the first member at an acute angle. A tangent line refers to a straight line along the circumferential surface in a vertical cross-sectional view; in Figure 2, the straight line representing the circumferential surface is the tangent line. The dimensions of each projection 11 are not particularly limited, and according to the manufacturing method of the present invention, they can be formed in a wide range, for example, on the order of several hundred micrometers to millimeters. That is, the height H of each projection 11, the diameter L1 of the part with the smallest horizontal cross-sectional area in the cross-sectional enlargement portion 11a (hereinafter referred to as "minimum horizontal cross-sectional area A1"), and the diameter L2 of the part with the largest horizontal cross-sectional area (hereinafter referred to as "maximum horizontal cross-sectional area A2") are, for example, on the order of several hundred micrometers to millimeters. Of the multiple protrusions 11, 11, ..., the distance D between the centers of the closest adjacent protrusions 11, 11 should preferably not be too large, from the viewpoint of increasing t