Ford: Award-Winning F-150
AJAC’s “Best New Innovation Technology” award goes to the Ford F-150 this year. Here’s how Ford managed to build a truck out of aluminum.
Aluminum is strong, light, and very corrosion resistant. But when it comes to using aluminum for vehicle body panels, those heady benefits are always offset by the increased cost of the material itself, a slower and more complex manufacturing and assembly process, and in the event of a road accident, more complex and expensive repairs.
Hence its heretofore restriction to higher-cost, lower volume applications, such as Land Rover, Jaguar, higher-end Audis, and various specialty makes and models.
So how did Ford manage to make the case for putting a virtually all-aluminum body (95 percent) on its super-high volume F-150 pickup? Here’s a review of the technology and strategic thinking that allowed them to pull it off…
Welding aluminum is tricky. So where typically steel panels are spot welded in the vehicle assembly process, the Ford pickup’s aluminum panels are bonded through a combination of rivets and industrial adhesive. Ford said it developed this expertise when it owned Land Rover and Jaguar; at that time both brands began using aluminum for frames and body panels. Still a complicated process, but Ford says it understands it completely. About 4,000 rivets effectively replaces about 7,000 spots welds.
Advances in computer modeling allowed engineers to create optimum shapes and thicknesses to further leverage the high strength-to-weight ratio of aluminum.
Ford uses both 5,000-series and 6,000-series grades of aluminum sheet supplied by Alcoa and Novelis. About half of the panels use the higher-grade 6000 series, which is both “smoother” (better for visible body panels) and stronger, owing to a heat-treated process. The panels get further heat treating when the body goes through the paint-drying oven.
Because aluminum is so light, engineers had the opportunity to actually make the panels “thicker” than regular steel panels — and still end up with weight savings. This furthered the durability required in this segment, and allayed fears about increased body-shop costs to repair body panels dings. Ford also designed F-Series from the get-go to have more replaceable body panels and frame sections. Check out the Edmonds.com series, where editors took a sledgehammer to the rear quarter panel of a new F-150, and then took it to a dealer for repairs.
To ensure F-150 customers will be able to have their aluminum panels repaired, dealers and independents will have to meet a Ford Aluminum Repair Certification requirement. Initially Ford Canada thought this might need a lot of encouragement, but soon realized how many dealerships were already into aluminum collision repair.
While body panels are aluminum, the ladder frame continues to be built of steel, and therefore continues to be made in an efficient time frame. But this time, 77 percent of the frame is constructed of high-strength steel, versus 23 percent in the previous frame. Ford said it had to pay particular attention to how the new aluminum body panels were fastened to the frame. After a simulated “six year” usage test, the team developed new ways to prevent scratching the e-coat corrosion protection on the frame and eliminated spots where the water would settle.
When equipped with similar powertrains, a new regular cab F-150 weighs about 260 kg (573 lbs) lighter than its predecessor, while the new Club and Crew Cab models’ weigh about 300 kg (661 lbs) less than their predecessors. About 30 kg of the weight savings comes from the new frame.