TY - GEN

T1 - Laser based repair of CFRP for the aerospace industry

AU - Wippo, Verena

AU - Hirt, Simon

AU - Dittmar, Hagen

AU - Jaeschke, Peter

AU - Kaierle, Stefan

AU - Overmeyer, Ludger

N1 - Funding Information: The authors would like to thank the Federal Ministry for Economic Affairs and Energy (BMWI) for funding these investigations within the project HyPatchRepair (20E1721B) of the German federal aeronautical research program.

PY - 2020/3/2

Y1 - 2020/3/2

N2 - Carbon fibre reinforced plastics (CFRP), particularly with a thermoplastic matrix material, have increasingly been used in the last decades. This is especially true in industrial sectors with a strong focus on lightweight applications such as the aviation industry. During the production of CFRP parts imperfections can occur resulting in the need of rework. Furthermore, a damage can occur in service time. In both cases, a large amount of carbon fibres and matrix material has to be mechanically removed, which comes along with high tool wear. Afterwards, the area has to be refilled. This is done by adhesive bonding of CFRP patches. Normal adhesives have long curing times of several hours. To enhance the repair process of thermoplastic CFRP, a two step laser based process was developed. In the first step, CFRP is removed by laser ablation, which allows a high reproducibility and accuracy. Goal is to generate a flat surface with a defined matrix amount. In the second step, laser heat conduction welding is used to refill the removed area with thermoplastic patches. This study was conducted with a carbon fiber fabric within a polyphenylene sulfide matrix. In order to develop a high quality heat conduction process, the ablation process was optimized to generate a defined surface. For the evaluation of the welding process, lap shear samples were welded with different setups. These samples were tested and fraction pattern evaluated.

AB - Carbon fibre reinforced plastics (CFRP), particularly with a thermoplastic matrix material, have increasingly been used in the last decades. This is especially true in industrial sectors with a strong focus on lightweight applications such as the aviation industry. During the production of CFRP parts imperfections can occur resulting in the need of rework. Furthermore, a damage can occur in service time. In both cases, a large amount of carbon fibres and matrix material has to be mechanically removed, which comes along with high tool wear. Afterwards, the area has to be refilled. This is done by adhesive bonding of CFRP patches. Normal adhesives have long curing times of several hours. To enhance the repair process of thermoplastic CFRP, a two step laser based process was developed. In the first step, CFRP is removed by laser ablation, which allows a high reproducibility and accuracy. Goal is to generate a flat surface with a defined matrix amount. In the second step, laser heat conduction welding is used to refill the removed area with thermoplastic patches. This study was conducted with a carbon fiber fabric within a polyphenylene sulfide matrix. In order to develop a high quality heat conduction process, the ablation process was optimized to generate a defined surface. For the evaluation of the welding process, lap shear samples were welded with different setups. These samples were tested and fraction pattern evaluated.

KW - Ablation

KW - CFRP

KW - PPS

KW - Repair

KW - Welding

UR - http://www.scopus.com/inward/record.url?scp=85083335313&partnerID=8YFLogxK

U2 - 10.1117/12.2540479

DO - 10.1117/12.2540479

M3 - Conference contribution

AN - SCOPUS:85083335313

T3 - Proceedings of SPIE - The International Society for Optical Engineering

BT - High-Power Laser Materials Processing

A2 - Kaierle, Stefan

A2 - Heinemann, Stefan W.

PB - SPIE

T2 - High-Power Laser Materials Processing: Applications, Diagnostics, and Systems IX 2020

Y2 - 4 February 2020 through 5 February 2020

ER -