Glimpses of Advances and Challenges in Lightweighting Impacting the Transportation Sector

The transportation sector accounts for almost 15% of global greenhouse emissions, and the consequent environmental and health effects are significant. Government legislation in the USA (and similar standards worldwide) have stipulated a corporate average fuel economy (cafE) of 4.32 L/100 km (54.5 US MPG) by 2025. Fossil fuel depletion, environmental consideration and the future of humankind have spurred a global quest for next generation vehicles. The direct consequence is lightweight and energy efficient automobiles. Low density and lightweight alloys and composites of aluminum (2.7 g/cm³) and magnesium (1.74 g/cm³) have replaced ferrous materials such as steel and cast irons (7.8 g/cm³) in automotive power train components in order to increase fuel efficiency. However, light alloy component development faces challenges in alloying, solidification processing, microstructural development, thermal properties and in-service performance. Interestingly, significant progress has been made in the mitigation of many challenges, and the journey continues. This lecture provides glimpses of mitigation, related mechanisms and the opportunities for the future.