Abstract Scope |
Abstract
There has been a significant awareness in the last few years among people all over the world about climate change caused by harmful carbon emissions. Many governments and companies have announced goals for significant reductions in carbon emissions. Automobiles are one notable source of carbon emissions through exhaust gas emissions. Therefore, for its part the automotive industry has been working diligently for the past two decades to reduce carbon emissions from vehicles. To accomplish this goal the automotive industry has had near term and long term goals. The near term goal for reduced vehicle carbon emissions has been steadily achieved through vehicle weight reduction. A study by the US Department of Energy study found that a 10% reduction in vehicle weight can save up to 8% in fuel consumption. For the long term goal for the next decade and beyond the industry has been working to eliminate dependence on fossil fuels through the development of alternative drive technologies, which include hybrid vehicles, electric vehicles and fuel cell vehicles. For the near term goal for a reduction in carbon emissions the automotive industry relied on the use of advanced high strength steels (AHSS), which provide high strength with good formability. The use of AHSS grades helped automotive companies achieve vehicle weight reduction without compromising occupant safety. Another way used for weight reduction was to use lightweight materials, such as aluminum and magnesium alloys, plastics, reinforced carbon fibers and composites. The use of these lightweight materials is projected to increase over the next two decades. As far as joining is concerned, fusion welding techniques have been the main stay of the industry for the past four or more decades. For example, Resistance spot welding is widely used in vehicle fabrication, more so in the body-in-white components. In recent years due to the use of mixed material in automotive production, adhesive bonding and mechanical fastening have emerged as significant joining techniques. As the use of alternative lightweight materials are projected to increase in the coming decades, there been an evolution in joining techniques required to join not only similar materials but combinations of materials as well. In this presentation the evolution of materials used in the automotive construction are reviewed starting from mild steel to the current Generation 3 AHSS grades. Further, projections on how material trends are likely to evolve are presented. A discussion on the predominant joining methods used currently is presented. Based on the projected materials usage, some discussion on the future trends in joining are presented.
Key Words: Automotive industry, Materials, Steel, Joining processes, Lightweighting |