Mechanical properties of ultrasonic welded and self-piercing riveted joints in a 5A06 aluminum alloy and a TA1 titanium alloy

The self-piercing riveting (SPR) experiences problems of poor forming qualities and mechanical properties during joining aviation alloy sheet materials. To address this issue, a novel combined process nominated ultrasonic self-piercing riveting (USPR) is carried out to join a 5A06 aluminium alloy and a TA1 titanium alloy sheets. The forming qualities, mechanical properties, failure modes, and mechanisms of USPR and SPR joints are comprehensively investigated. The results showed that the mechanical properties of the USPR joints were enhanced due to the welding formation of a solid phase between the specimen sheets and the degree of solid phase. The investigation showed that the welding was mainly affected by the material of the upper sheet. However, the welding also increased the brittleness of the rivet to some extent. The failure modes of the joints are affected by the welding process. The results determined that APL, AFD, and AEA of USAA joints were improved by 25.6 %, 31.3 %, and 88.8 %, respectively. The performance of the USPR joints with 5A06 aluminum alloy as the upper sheet is improved more than 88.8 % after the welding process. The combined method can be advantageous and supportive for automotive and spacecraft applications.