TWI Technical Literature Review 23022
By S M Smith
The automotive industry is going through a state of change. Since the advent of mass production in the early 20th century, extremely fast, reliable high volume use has been made of sheet metal to make cars. The joining technique that allowed this scale of mass production in the car industry was resistance spot welding. Consequently the high volume car industry was predominantly a resistance spot welding industry, resisting anything that would upset the economic benefits of the spot welding process. The preferred material used for car manufacture was low carbon sheet steel, because this material most suited the industries main requirements of; formability, strength, ease of production and spot weldability.
Over the last 20 years this situation has been changing, firstly with the introduction of more exotic coated steel and high strength steels, and later with increasing volumes of 'new' materials such as aluminium, plastics and stainless steels. Today the car industry has a new approach; nearly all car manufacturers have a future multi materials strategy (not just the high end performance vehicle makers), seen as the best and most economical way of achieving the combination of light weight and high structural strength required for future vehicle emissions targets, M White .