이종재 Al/CFRP 마찰교반점용접시 에폭시 접착제 유무에 따른 접합특성 평가

다국어 초록 (Multilingual Abstract)

ABSTRACT


Effect of epoxy adhesive on Joining Characteristics
of Dissimilar Al5052-CFRP

Park Jae-Woo
Advisor : Prof. Bang, Hee-Seon, Ph.D.
CO-Advisor : Prof. Bang, Han-Sur, Ph.D.
Department of Welding and Joining Science Engineering,
Graduate School of Chosun University


In recent years, regulations on automobile emissions and fuel consumption have been gradually strengthened. Vehicle weight reduction has become an essential element in the automotive industry. Hot stamping, hydro-forming and other methods are adopted to lighten the vehicle. However, it is difficult to meet the tightening regulations. Therefore, In this study, we are trying to satisfy the emission gas and fuel efficiency regulations of automobiles by using lightweight material, which is not a new method for lighter vehicles.

There are many materials such as super high tensile steel plate, non-ferrous material and carbon fiber reinforced plastic as lightweight materials, among which Al and CFRP were selected. There are many methods such as SPR and the like as the joining method between Al and CFRP, but FSJ is selected among them.
The purpose of this study is to improve the bonding between lightweight materials (CFRP and Al alloy) by using friction stir welding and epoxy adhesive. The materials used were CFRP (PA66) with a thickness of 1.5 mm and Al alloy (Al5052) with a thickness of 1.0 mm. The Al alloy was placed on top of the CFRP and overlapped. In order to increase the joint strength by causing interlocking phenomenon between materials, 5 surface roughness was given by Wet-Grinding to the bonding surface of Al alloy.

The process variables include tool rotation speed, plunge depth, and dwell time. Mechanical and metallurgical properties of the joints were evaluated by friction stir welding, adhesive bonding, and hybrid bonding. In this study, thermal distribution characteristics of Al/CFRP joints were investigated using numerical analysis program and compared with the experiment.

As a result, maximum tensile-shear strength in Friction Spot Joining was obtained approximately 3.3kN(400rpm, 0.3mm, 25s) and bonding with adopted adhesive was obtained approximately 6.4kN(400rpm, 0.2mm, 25s). Also, tensile shear strength in adhesive bonding was achieved approximately 6.1kN. The effect of bubble formed in the specimen and surface roughness is also considered in accordance with the results of tensile-shear strength.

목차 (Table of Contents)

• CONTENTS
• List of Figures Ⅲ
• List of Tables Ⅴ
• Abstract Ⅶ
• 1장. 서론 1
• 1.1 연구배경 및 목적 1
• 1.1.1 연구배경 1
• 1.1.2 연구목적 5
• 1.2 국내 외 기술 동향 6
• 1.3 마찰교반점용접(FSJ) 9
• 1.3.1 마찰교반점용접의 원리 9
• 1.3.2 마찰교반점용접의 특징 11
• 1.4 Al(5052)/CFRP(PA66) 소재의 특징 12
• 1.4.1 알루미늄합금 12
• 1.4.2 탄소섬유강화플라스틱(CFRP) 13
• 1.5 구조용 접착제의 특징 14
• 2장. 연구 방법 15
• 2.1 실험방법 15
• 2.1.1 사용소재 및 시험편 제원 15
• 2.1.2 실험장비 및 툴 18
• 2.1.3 접합조건 20
• 2.2 접착제 유무에 따른 접합부 특성 평가 24
• 2.2.1 단면 및 접합 계면 관찰 24
• 2.2.2 인장-전단시험 24
• 2.2.3 미세조직 관찰 25
• 2.2.4 접합부 온도분포 수치해석 26
• 3장. 연구 결과 34
• 3.1 접착제 유무에 따른 마찰교반점접합부 특성 34
• 3.1.1 마찰교반점접합 접합부 특성 평가 34
• 3.1.2 접착제를 채용한 마찰교반점접합 접합부 특성 평가 52
• 3.1.3 접착제 유무에 따른 마찰교반점접합 특성 비교 평가 64
• 3.2 표면조도에 따른 Al/CFRP 접합부 특성평가 66
• 4장. 결론 66
• 참고문헌 67