Interfacial wear damage of CFRP/Ti-alloy single-lap bolted joint after long-term seawater aging

• The interfacial wear damage in CFRP/Ti-alloy hybrid joints can be effectively inhibited by the surface treatment of Ti-alloy. • The stability of the transfer lubrication film formed during wear process is critical to the damage evolution of CFRP. • The aging time and temperature exaggerate the hygrothermal effect of CFRP, weakening the fiber-matrix interface and intensifying the wear damage. • The influence of salt concentration depends more on the presence of salt ions rather than their concentration. Interfacial wear damage is one of the primary causes of joint failure, especially in the marine environment since material aging greatly aggravates the wear damage between the contact interfaces of joint. In this paper, interfacial wear damage mechanism of CFRP/Ti-alloy single-lap bolted joint after long-term seawater aging was researched through the wear experiments and material microstructure analysis. The results show that CFRP demonstrates strong tribological anisotropy where 0° wear shows more serious wear damage than 90° wear. The wear damage of contact interface can be inhibited by surface treatment of Ti-alloy through reducing the hard contact. Long-term seawater aging has significant impact on the wear damage evolution of CFRP. The aging time and temperature exaggerate the hygrothermal effect, weakening fiber-matrix interface and intensifying the wear damage. The influence of salt concentration depends more on the presence of salt ions rather than their concentration.