Comparison of Self-Pierce Riveting, Resistance Spot Welding and Spot Friction Joining for Aluminium Automotive Sheet 2006-01-0774
This work compares three aluminium sheet joining processes to determine their capability, efficiency and cost for mass production applications in automotive structures and closures. The joining processes investigated are Resistance Spot Welding (RSW), Self-Pierce Riveting (SPR) and Spot Friction Joining (SFJ). Quantitative comparisons have been made on the basis of tensile strength (shear and peel), process time, equipment price and running cost.
RSW is the most commonly employed joining method for steel sheet in the automotive industry. Its principle benefits are high speed and low cost operation, plus the ability to weld a wide range of joint configurations with the same gun. The main process limitations for aluminium are weld consistency and electrode-life, though recent work has shown that both of these can be largely overcome with regular electrode polishing [1, 2].
SPR is already in use for volume production of aluminium body structures. Its principle benefits are superior mechanical strength and ability to join dissimilar materials. The main process limitations are the ongoing piece cost of the rivets and the limited range of joint configurations achievable on each gun. End-of-life recycling of aluminium parts is more complex when they contain steel rivets.
SFJ is derived from friction stir welding technology, its principle benefit being rapid low cost joining of thin sheet. SFJ can join some of the commonly used automotive alloys and is low in power consumption. The process is presently limited to simple joint configurations and requires long process times to join thick sheets.