Aluminum Inferior To Steel? Not On The 2015 Ford F-150 – Forbes
No matter how the Ford research group in charge of rethinking the F-150 pickup looked at the issues, it was always the same answer that popped up.
“If you can use technology and materials to take weight out of the vehicle, you’ll always end up with the best solution,” says Pete Reyes, chief engineer of the 2015 Ford F-150.
The main goal in developing the new full-size pickup, which goes on sale later this year and has sparked controversy over its weight-saving aluminum body, was to increase efficiency without compromising capability. Alternative powertrains were considered, so was downsizing, but always it came back to the weight, Reyes says—the less of it, the better.
The solution that the team came up with was revolutionary as pickups go: Use an aluminum body instead of a steel one to cut 700 pounds from the vehicle in one fell swoop. But the change had its detractors, both inside and out of the company, Reyes says. To some, aluminum was nothing more than the stuff of soda cans; it could not possibly stand up to the severe abuse pickup trucks must endure.
The United States Military and big-rig trucking companies beg to differ, Reyes says. Humvees and Peterbilts have long used steel frames with aluminum bodies, much as the new F-150 does. (Yes, we know, military vehicles often get armor plating made of steel, but some versions don’t and stick with aluminum for certain body panels instead.)
The real proof of concept came in sneaking aluminum-bodied F-150 prototypes that looked like the current version into commercial fleets, and even a Baja 1,000 race, incognito.
In the edited interview below, Reyes shares the results of these unconventional fields tests and debunks some myths concerning aluminum’s strength, or lack thereof.
What kind of aluminum is the 2015 F-150 made out of?
The majority of the truck body is 6,000-series alloy aluminum, which is a heat-treatable alloy aluminum. Depending on the mix that you put in the alloy, but certainly more a function of how long you heat treat it, you can get all manner of properties out of this aluminum. Some of our structural elements and our extruded pieces are heat treated, and we end up with stronger pieces than the steel we’re replacing.
So the aluminum is actually stronger than steel? How is that possible?
Two real simple tricks. You can just choose to heat treat it to a strength and replace it with a steel part that just happened to not be as strong. But you can also just add gauge [i.e. make it thicker]. Aluminum being a third as dense as steel, you can have three times the thickness before you have the same weight as steel. So in a lot of cases, we tailored it to the strength we needed.
People are asking, “How do you have more dent and ding resistance?” Well, aluminum actually has better properties for dent and ding resistance, but we can also just up-guage it another tenth of a millimeter and still save 40 percent of the weight.
So if aluminum parts can be made to be as strong or stronger than steel ones, why hasn’t Ford done this before?
We could have done this truck 10 years ago, but it would have taken us eight years to design, because we didn’t have the computer-aided engineering tools for aluminum like you have for steel. We’ve been maturing them through developing aluminum hoods and liftgates [for other vehicles]. When Ford owned Jaguar and Aston Martin, our aluminum group did a lot of that work. So now you’ve got tools that engineers can use that can keep up with what is typically a three-and-a-half-year design cycle. That was probably the big breakthrough in this proposition.
What about cost for repairing aluminum versus steel in the event of a crash?
Aluminum always is more expensive than steel on a per-pound basis, but a couple of things we’ve come to understand are: Very few vehicles every year actually need heavy repair, but even when it comes to replacing panels, the fact that you can just grind out the rivets and not have disturbance to the base metal and just pop in a new panel, we’ve been told, that’s pretty simple and elegant. So we’re not concerned about it and we’re preparing to make this very accommodating to the customer.
So the aluminum panels are riveted to the steel structure, which is different than how steel panels would be affixed?
Yeah, there’s a lot more rivets in aluminum panels than in steel. Steel has a lot of spot welds all over.
What sort of field testing did you do?
We’ve had current F-Series trucks made entirely out of aluminum running around since 2009. So we said, let’s take one of our old test trucks and let’s put it in the Baja 1,000. So we went out with our new EcoBoost powertrain, which is all-new for this vehicle, we put the frame that’s going in the 2015 model, the suspension that’s going in the 2015, and then the upper body looked like the current truck but it was made entirely out of aluminum, and we ran the Baja 1,000. We finished with not a crack in the body panels. So that was fun. Now we can come back and show that truck and say, “Aluminum isn’t tough? Look at it. Feel it. Touch it.”
We also sent out trucks with aluminum boxes to some of our extreme users. One of them was Walsh Construction. I actually visited Walsh one time and we told them, “Hey, your truck has some changes to it. We’re giving it to you for free. Use it as you normally would on your site. We’ll come by and check it out.” And we’d go by and we’d ask: Does it feel different? Does it behave differently? Did you notice that it cracks? And we’d take full engineering analysis of it and these guys never knew, they never knew it was aluminum.
What did you learn from these extreme field tests?
We came away with certain areas, let’s beef this up, let’s pay more attention here. But probably came away most encouraged by finding that the aluminum is just as good as our steel box, so let’s make it better. Let’s go up-gauge some things and try to make it more dent and ding resistant.
And it’s eye-popping to see what they do in the heavy construction world with a pickup truck. The equipment, the tools, the things they just fling in back there. The amount of abuse that it takes, both on the outside of the truck and inside the bed, is remarkable. But it’s just a tool for these guys, they don’t care that it’s all dented and dinged up.
Can you give an example of some extreme abuse?
We were surprised that they’d take these big railroad hitches and throw them in the back of the truck. And these pintle hitches, which is what they’re called, would pierce boxes, whether it was a steel box or an aluminum box. We couldn’t believe that these people were so willing to dent or puncture their boxes. But we said, “If this is really what they do, let’s invent a test and let’s use this as something to guide us on our box floor.” And so we took sort of the basic shape of this pintle hitch, the weight of it, and we dropped it from three feet, or whatever it was.
And the verdict was that the new aluminum F-150 cargo box holds up better than the previous steel one?
Yeah, absolutely. Our new box is better in Ford’s “pentle hit test.” GM and Toyota, they won’t know what we’re talking about. It’s just a Ford internal test we developed for the fun of it. We wanted to do a better box floor.