이종소재 기판 간 접합성능 향상을 위한 로봇 기반 3차원 레이저 공정 표면 앵커 구조화 연구 = Robot-Assisted laser processing of anchor structuring for improving hetero-materials substrate bonding

다국어 초록 (Multilingual Abstract)

This study demonstrated a six-axis robot-assisted nanosecond laser texturing approach for fabricating high-aspect-ratio surface-tilted micro-structures to enhance direct metal–polymer joining. By precisely controlling the laser incidence angle and inter-line pitch together with an overlap strategy for heat-affected zones, recast layer accumulation was promoted, allowing the formation of high-aspect-ratio micro-structures without thermal distortion of the metal plate. The spatial flexibility of the robot enabled reliable fabrication of inclined surface features, which increased both the effective joining area and mechanical interlocking capability. Adaptive control of the laser scanning path suppressed out-of-plane deformation during large-area processing, while point-to-point beam steering allowed the fabrication of geometrically diverse surface patterns such as groove lines, circular forms, and wobble structures. Tensile testing revealed that groove-line specimens showed direction-dependent reinforcement, with strength increasing up to 7.72× at 0° tilt and 13.41× at 8° tilt when the applied load was perpendicular to the grooves, whereas the interlocking effect was reduced under parallel loading. In contrast, wobble-structured specimens exhibited isotropic interlocking behavior, maintaining consistent strength regardless of the loading direction and achieving enhancements of 11.01× at 0° tilt and 14.11× at 8° tilt compared with the unstructured reference. These results confirm that robot-guided laser texturing enables scalable and precise fabrication of high-performance micro-structures and provides flexibility in designing their geometry and orientation for various applications. In particular, the wobble-formed structures, characterized by randomly distributed tilt orientations over 360 degrees, exhibited direction-independent anchoring, offering a scalable and adhesive-free method for integrating metal–polymer hybrids suitable for lightweight and high-strength components in automotive, aerospace, and related industries.

목차 (Table of Contents)

• 1. 서론 1
• 2. 이론 및 연구배경 4
• 2.1. 금속-폴리머 접합 4
• 2.2. Direct-Laser 공정 특성 8
• 2.2.1. Laser 발진 8
• 2.2.2. 가우시안 레이저 빔 12
• 2.2.3. 레이저 반사 및 흡수 14
• 2.3. Structure 16
• 2.3.1. 패터닝 16
• 2.3.2. Mechanical interlocking 18
• 2.4. Laser beam 경로 제어 24
• 3. Laser Texturing 공정설계 29
• 3.1. Laser Texturing 시스템 구성 29
• 3.1.1. Nanosecond laser 29
• 3.1.2. 6-axis Robot 31
• 3.2. Micro-structure 35
• 3.2.1. Laser Structuring 공정설계 35
• 3.2.2. Inter-line pitch에 따른 Laser structure 가공 특성 분석 38
• 3.2.3. 레이저 빔 간격에 따른 소재 Bending 현상 분석 46
• 3.2.4. 표면 앵커 구조화 50
• 4. 대형기판의 표면 Anchor 구조화를 위한 Laser Texturing 57
• 4.1. 대형기판의 레이저 열 누적에 따른 금속판의 Bending 현상 57
• 4.2. 패터닝 종류에 따른 Anchor Structure depth 평가 59
• 4.3. Anomalous array를 활용한 대형기판의 Bending 개선 64
• 5. 이종소재 기판 간 접합 성능평가 71
• 5.1. 접합 성능평가용 금속 시편 제작 71
• 5.2. 이종소재 기판 간 레이저 투과 73
• 5.3. 이종소재 기판 간 인장강도 평가 78
• 6. 결론 및 제언 82
• 참고문헌 83
• 영문초록 88