Aluminum: Toward 50% body content

To vehicle-development teams, peaceful coexistence is the 2020's way of describing the relationship between steel and aluminum. Sure, the two giant materials industries will continue their battle to conquest one another's market share. But for vehicle planners and program-development teams, the ferrous and light metals are an increasingly effective and popular combination. As experts Dr. Alan Taub and Michael Robinet have noted elsewhere in this issue, the mixed-materials trend is becoming an enduring one, as evidenced across the landscape of recent new-vehicle introductions.

Aluminum crossmembers and subframes are engineered harmoniously into light-truck ladder frames whose finely-tailored use of various advanced high-strength steel grades could fill engineering textbooks. Suspension control arms have become the focus of new CAE-driven designs that have brought flip-flop applications within some OEMs-what was once a heavy steel fabrication is changed to a far lighter aluminum casting, then to a forging, only to be transformed again into an even lighter steel stamping full of precisely-located lightening holes. Further iterations in aluminum-or perhaps CFRP composite, or a combination of metal and composite-are likely to follow.