Dissimilar Material Joint Recess Geometry for Multi-Directional Strength

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Solution Overview

Problem

Existing methods for joining dissimilar materials result in low joint strength in certain directions, leading to easy separation of the materials.

Innovation Solution

Forming first and second recesses on a surface of a first member at oblique angles, with a second member engaging these recesses to enhance joint strength by melting and solidifying within them.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a surface is irradiated with laser light in one irradiation direction to join dissimilar materials, then the joining process is simple, but the joint strength against separating load along that direction is low

Engineering Contradiction:
Improvejoining process simplicityVSAvoidjoint strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent applies asymmetry by forming recesses with different orientations (first recess at first oblique angle, second recess at second oblique angle different from the first). This asymmetric configuration ensures that the joint has strength in multiple directions, eliminating the low-strength direction problem while maintaining manufacturing simplicity through a systematic laser processing approach.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent transitions from a single-direction (one-dimensional) laser irradiation approach to a multi-directional approach by forming recesses at different oblique angles. This dimensional change in the laser processing approach creates a multi-faceted joint structure that resists separating loads from multiple directions, thereby improving joint strength without significantly complicating the manufacturing process.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Strength

If multiple recesses are formed at different oblique angles to eliminate low-strength directions, then joint strength is improved, but the complexity of the joining process increases

Engineering Contradiction:
Improvejoint strengthVSAvoidjoining process complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent segments the laser processing into distinct stages: forming the first recess at a first oblique angle, then forming the second recess at a second oblique angle. This segmentation allows each recess to be optimized independently for strength in specific directions, while the overall process remains systematic and controllable, balancing complexity with performance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs preliminary action by first forming the recesses with specific orientations before applying the dissimilar materials. This pre-configuration of the substrate structure ensures that the joint will have predetermined strength characteristics in multiple directions, eliminating the need for complex real-time adjustments during material joining and thereby controlling process complexity.

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If dissimilar materials are joined with single-direction laser irradiation, then the process is straightforward, but the materials are easily separated under load

Engineering Contradiction:
Improveprocess straightforwardnessVSAvoidresistance to separation
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The asymmetric arrangement of recesses at different oblique angles creates a joint structure that is reliable under separating loads from multiple directions. The asymmetry ensures that no single direction is a weak point, thereby improving reliability while maintaining a straightforward systematic processing approach.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent applies local quality by creating specific localized structures (recesses with different orientations) at different locations on the substrate surface. Each local region (first recess area, second recess area) is optimized for resisting separation in specific directions, and the combination of these localized optimizations provides overall high reliability against multi-directional separating loads.

Inventive Principle:
Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The method increases joint strength by eliminating low-strength directions, suppressing separation of dissimilar materials, and reduces energy requirements.

Implementation Method 1

forming a first recess and a second recess by irradiating a surface of a first member with laser light

Methodology Applied
Scientific EffectLaser heating: Laser

Implementation Method 2

irradiating a surface of a first member with laser light, the first recess and the second recess being cut into the surface

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 3

joining a second member to the surface of the first member with a part of the second member engaging with each of the first recess and the second recess by melting the part of the second member lower in melting point than the first member

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 4

solidifying the part of the second member

Methodology Applied
Scientific EffectSolidification: Freezing

Data Source

PatentEP4155059B1Method for joining dissimilar materials and joint of dissimilar materials
Publication Date: 2025.11.05 DAIHEN CORP
  • EP4155059B1 patent drawingFigure 1
  • EP4155059B1 patent drawingFigure 2~3
  • EP4155059B1 patent drawingFigure 4~5

AI summary

A method for joining dissimilar materials includes forming a first recess (100) and a second recess (110) by irradiating a surface of a first member (10) with laser light, the first recess (100) and the second recess (110) being cut into the surface obliquely at angles different from each other, and joining the second member (20) to the surface of the first member (10) with a part of the second member (20) engaging with each of the first recess (100) and the second recess (110) by melting the part of the second member (20) lower in melting point than the first member (10) to cause the part of the second member (20) to flow into each of the first recess (100) and the second recess (110) and solidifying the part of the second member (20).