A new method of hybrid friction stir welding assisted by friction surfacing for joining dissimilar Ti/Al alloy

[Display omitted] •A novel method of friction surfacing assisted hybrid friction stir welding was proposed to join dissimilar metals.•The tensile load of Ti/Al joints was improved to 12.2kN, reached 85.3% of the Al base material.•Tool abrasion was totally avoided by introducing a friction surfaced Al-coating layer.•The bonding was combined contribution of nanoscale-IMCs and mechanical interlocking. A new method of friction surfacing assisted hybrid friction stir welding (FS-HFSW) technique was developed to improve the joint efficiency and avoid the pin abrasion for joining of dissimilar Ti/Al joints. The FSW tool with enlarged head and concave end-face was designed to broaden the lap width and promote material flow. The maximum tensile load reached 12.2kN, representing 85.3% of the parent Al alloy, with a ductile fracture locating at the heat affected zone of base Al. The excellent bonding of Ti and Al was based on the combined effects of nanoscale TiAl3 IMCs layer and complex mechanical inter-locking.