A newly designed Ni-P duplex coating on friction stir welding joint of 6061-T6 aluminum

Authors：Chen, Jiahuan; Wang, Yuxin^*; Gao, Wei; Wang, Dongpeng; Chen, Shujin^*; Luan, Junhua

Source：Surface and Coatings Technology, 2022, 448: 128940.

DOI：10.1016/j.surfcoat.2022.128940

• FSW joints
• Anodic oxidation
• Electrodeposition
• Corrosion protection
• Wear resistance

Friction stir welding (FSW) joints often require coatings with good adhesion and corrosion resistance to improve durability. In this research, a newly designed duplex Ni-P coating was fabricated on the FSW joint of 6061-T6 aluminum alloy. An anodic aluminum oxide (AAO) layer was formed on the joint substrate as the intermediate layer to enhance adhesion, and a Ni-P layer was then electroplated on top to strengthen the corrosion and wear properties. The bonding strength, anti-corrosion property and wear resistance of the duplex Ni-P coating were investigated systematically and compared with those of the traditional zincated Ni-P coating. The duplex Ni-P coating results in superior adhesion and significantly improved anti-corrosion property than traditional Ni-P coating. The friction property of the FSW joint with duplex Ni-P coating is 88 % higher than that of the original FSW joint and 75 % higher than that of the FSW joint coated with traditional Ni-P coating. The related mechanisms were discussed in detail.

• Institution
  江苏科技大学