| About this Abstract |
| Meeting |
Materials Science & Technology 2020
|
| Symposium
|
Substrate Protection for Corrosion Prevention
|
| Presentation Title |
Effect of Surface Coating and PTFE Tape Insulation on Galvanic Corrosion of AZ31B Bolt-joined with CFRP |
| Author(s) |
Charles David Warren, Jiheon Jun, Yong Chae Lim, Zhili Feng |
| On-Site Speaker (Planned) |
Yong Chae Lim |
| Abstract Scope |
Magnesium (Mg) alloys and carbon fiber reinforced polymer (CFRP) are of high interest for lightweight vehicles. Although bolting can achieve reliable joints for multi-materials auto-body structures, galvanic corrosion of Mg in contact with CFRP and steel bolt is a great concern. To mitigate galvanic corrosion, electrical isolation between Mg, CFRP and bolt was attempted. In this work, bolted specimens of AZ31B and CFRP were prepared with and without surface coating between AZ31B and CFRP. Polytetrafluoroethylene tape applied on the steel bolt as an insulation layer. Then, the bolted specimens were tested by 0.1M NaCl immersion and ASTM B117. Corrosion potential of the bolted samples with isolation in 0.1M NaCl was closer to Mg corrosion potential, suggesting weaker galvanic polarization. The corrosion depth measured on AZ31B in the joints was significantly smaller with isolation case. Lap shear tensile testing of the post-corrosion specimens with isolation showed less degradation of joint strength. |