Enhanced the bonding reliability of titanium alloy and CFRTP via interfacial multiple modification: Synergy of physical interlocking and chemical interaction

A novel multiple modification approach including laser texturing, micro-arc oxidation process and silane coupling agent treatment was proposed to optimize the bonding interface. Firstly, laser texturing was fabricated to promote the mechanical interlocking. Secondly, the micro-arc oxidation porous structure was designed to modify its physical structure and chemical states. This promoted the interfacial mechanical interlocking in dual scales including texturing and porous structures. Moreover, the new chemical bonds such as Ti-C and Ti-O were generated at the interface. The bonding strength of TC4/CFRTP was enhanced from 10.23 MPa to 23.41 MPa. Besides, more hydroxyl groups (–OH) were adsorbed inside the optimized structure, and the hydrogen bonds were successfully induced by silane coupling film via the final step. This further enhanced the bonding strength to the maximum of 27.22 MPa. Therefore, the multiple modification approach realized the comprehensive enhancement of mechanical interlocking, chemical bonding and functional groups interaction, which enhanced the bonding reliability by 166% than pretreated case. These results benefit future research in the process optimization to improve the reliability of metal-CFRTP bonding structures.