@TSMB, I think there are specific traits of CF that make it ill-suited to structural use in automobiles. (Non-stressed body paneling is a different issue…CF is okay there, if money’s no object.)
Money. Aviation is priced such that a premium material can be tolerated somewhat. Non-exotic automobiles, not so much.
Lack of “plastic deformation” in an accident. Metal tends to bend in a crash; heck, “bend some metal” is a euphamism for “wreck.” This failure mode absorbs energy that otherwise would get transmitted to the passengers. Composites, OTOH, “snap” (like wood) when limits are exceeded. Not such a big deal in aviation, where passenger safety centers almost entirely on “don’t wreck”; rather bigger deal on the roads.
Delamination. One well-placed rock can start a catastrophic failure of CF. Not sure I’d trust anyone to patch structural CF. Alaska Air is the only domestic carrier I know that flies to gravel runways; how many Dreamliners have THEY ordered?
Fatigue failure. CF “pressure vessels” are generally “cycle limited” by the FAA: time will tell if that’s overly cautious or not. I know I’d sooner let the “early adopters” figure this one out for me.
Galvanic corrosion. Early CF bicycles were CF “tubes” with metal “lugs” joining them into a traditional “double triangle” frame. These generally failed early and were “throwaway” frames. Can CF autos behave any better with the steel parts bolted to it…in the presence of road salt? Color me skeptical. (Note that runways are NOT salted!)
Disposal. Fe and Al are readily melted down and re-used; they have intrinsic value that makes littering them about fiscally stupid. CF consists of charcoal and cured epoxy resin, neither of which are readily broken down into anything useful. I have a lot more faith in eco policies that rely upon innate human greed vs those that require everyone to develop an eco-conscience simultaneously!
BONUS: Don’t forget CF weakening in the heat, and the difficulty of using a “chassis ground” system!
This may be one of those situations where one has to wait and see how it works out in the long run. As with most things of this nature, the public usually becomes the lab rats…
I also wonder about carbon fiber over the long haul. The old fiberglass Corvettes looked good and held up well but at some point age and the environment would start causing that fiberglass to crack and delaminate.
Being curious a quick look and a cut and paste from the title of this story might raise a few eyebrows. Seven feet of wing peeling loose would make me a bit antsy…
FAA levies large fine against aircraft OEM for wingskin bond failure
During an FAA audit test flight in December, the carbon fiber composite skin on the left wing of a Cessna Corvalis separated from the forward spar and damaged a fuel tank. Excessive humidity in Chihuahua, Mexico, plant is blamed for the failure.
Everyone of these construction materials has durability subject to their engineering as much to their composition. They can all vary significantly in the same family. So, you really can’t generalize about one being better then another without know it’s application and engineering. Heck, I have seen wood fair much better for some truck bed use then most materials you can think of. Except for the weight, wooden truck beds would be a tough sell for most new truck buyers of half tons.
Some of the strongest construction composites have compressed injected foam cores with plastic layers. I have boats made from is process. The only boat of this type to have a known hole put through the hull was one that fell off a truck bed and hit a bridge abutment. It was repaired and in the water days later. There are some amazing materials and some of the longest lasting are found in marine environments. You won’t find them in cars…except for some of the bumpers. They are too good.
Cost is extremely important in aircraft. But in aircraft, the cost-per-pound to fly the aircraft is high, such that the cost savings by weight reduction exceed the additional cost of manufacturing much more readily than in a car. .
Carbon fiber composits “snap like wood”? Allow me to suggest you do some research on the properties of car carbon fiber composits. They can fold like fiberglass, because they’re very similar with the exception of the fibers, but they don’t snap. But it’s also very well known how to direct forces in a crash with CF.
Carbon fiber ill-suited for structural use in automobiles? CF is much stronger per weight than steel or aluminum. All of the fastest cars in the world are built around carbon fiber monococque (sp?) bodies. It is extremely structurally strong. Its only drawback is cost. I suggest you consider the use of CF by Bugatti, Pagani, Ferrarri, Lamborghini, and every other supercar maker in the world. The structures of these cars are almost entirely CF.
CF does not delaminate. It is not a laminate to begin with. It’s an impregnation.
All materials requires routine and often inspections for fatigue failure by the FAA. Aluminum requires a great deal of Non Destructive Inspection (called NDI) that includes radiographics and other NDI techniques at specific “flying hours”, depending on the category of aircraft. Monitoring aircraft for stress failure is a routine part of flying. Would you fly in an aircraft that wasn’t NDI inspected on a routine scheduled basis?: I wouldn’t. And I LIVED with aircraft for four years.
Yes, there were bonding failures and lug failures with the early carbon fiber bikes. But it was not the CF itself that failed. And it is a well established material for automotive use (see (2) above. Working with CF has had a learning curve, as do all new materials.
Properly cured CF will not weaken in the heat. Electrical grounds need toe be run as “buss wires”, but that’s no biggie at all, not even a little bit.
Recycling is a problem as far as I know, however I’m sure that isn’t insurmountable.
To better understand the strength of carbon fiber, allow me to suggest you do some research. Carbon fibers are currently considered the strongest (per weight) fibers known to man.
Carbon Fiber is a very expensive material to build a car out of (right now) but it is very strong and durable, The Saleen S7 for example could be jacked up at pretty much any place on the underside and they only put teflon skids to help the car from hanging up on driveways. There have been demonstrations by Tom&Ray on tv where Ray whaled on a carbon fiber body with a sledge hammer with no damage. You can break carbon fiber but it takes a lot of force. If the cost goes down more companies will be taking advantage.
Interestingly, the whole concept of using impregnated strong fiber mats for cars has an interesting history. One of the car mags, I think Top Gear, just did an article on Bruce Meyers and the invention of the Meyers Manx. The Meyers Manx is a fiberglass “tub” onto which aircooled VW Beetle parts are bolted to create a dune buggy. Bruce was molding fiberglass surfboards and boats in 1964 when he decided to mold a fiberglass monococque body on which to bolt VW parts to ride the sand dunes. He did so, and, according to him, when he first took it out on the dunes he expected it to break in half. It had no frame. It turned out to be far stronger and more capable than he ever expected. And he thus created an icon. Interestingly, the hypercars we’re referencing use exactly the same molded-tub monocoque concept, only in carbon fiber.
And as I mentioned earlier, carbon nanotubes are the strongest fibers currently known to man.
Having already owned a car with a flimsy aluminum body, I hope Ford’s aluminum body is more sturdy than the metal used on my Honda Civic. I wouldn’t want a workhorse-type of truck that can’t take real truck-type use.
Well Folks, good enough is good enough,when we get out of the Marvel comics mindset(and DC) we will have an epiphany of strong enough is good enough.Joe blow will never ever be able to afford what the Military and Law enforcement cannot destroy,Big Brother will always be one step ahead-why do you think hi performance aircraft are so unobtainible(crack the spar indeed)-Kevin
Speaking of alloys … here’s the next inevitable question ;
When you replace a damaged aluminum body panel…
Can you take the old one to the recycling center with your soda/ beer cans ?
They’ve gotten pretty picky about , at least , separating the types ; like cans / foil / tabs all separated plus the aluminum car parts like oil pans, wheels, and mounting brackets all have a different value.
When I heard about the aluminum body F 150, it made me think back to the early 1950s. Our neighbor had a Ford Model A pickup truck that he painted with aluminum paint. Maybe I’ll buy up old Ford F-150 trucks, get a spray gun and some aluminum paint and go into business for those who want the latest with the real aluminum body F 150 but can’t cut the price.
MT seems to have gotten the details right…or at least different…from the article first linked.
Body panels and bed Al. Frame steel…but hi-strength alloys vs. plain ol’ mild steel.
That’s about how I’d hope they’d do it. The BIG Mack dumps use Al beds, so it oughta work on a 1/2 ton. If done right, there shouldn’t be galvanic corrosion issues. At any event, I’d be in the market for a '14 F150 around 2024, so we’ll know before then if they got it right or not.
I can see the aluminum bodies being both good and bad. The weight reduction will allow Ford to meet better CAFE standards in 2016. I expect to see more makes going this route although new cars will likely become more expensive. The good news is less susceptibility to corrosion.
Some have brought up body repairs. I know working with aluminum is much harder than steel. This will make welding and such a bigger deal on these trucks and others that will likely follow.
I would expect fatigue has been accounted for and that they are not going to release something that is going to crack in no time. As others have indicated, aluminum has been used in aircraft and some heavy trucks for some time. The Dehavilland Comet was the first of its kind and some unforeseen issues began to crop up relatively soon. The strong but very lightly constructed aluminum alloy skin was subject to fatigue. The early generation square windows tended to concentrate stresses at their corners. Finally, certain early models began popping like a balloon as they were flying to their destination.
I once watched a National geographic special on this incident called “Seconds From Disaster”. The name of the episode is “Comet Air Crash”. I would post a link to a favorite video sharing site but posted links seem to not always get posted. You should be able to use my description to look it up yourself. I found this episode and several others in the series to be quite interesting and informative. They went into details about the forensic investigation and destructive pressure cycling of the aircraft fuselage. Several other episodes pertain to air crashes with many having to do with metal fatigue of pressurized fuselage or components within jet engines themselves such as in the Sioux City DC-10 crash.
That being said, incidents like this are becoming increasingly rare and investigations after such disasters reveal flaws that are then hopefully corrected in future generations. While Ford may not design to quite the same levels as the aviation industry, I would expect this to be the least of the concerns with the new material.
I would also expect the aluminum panels to be 100% recyclable just like any other aluminum material. I don’t know which category this would fit into but know that there are slightly different prices for cast aluminum, cans, and such. That being said, I would love to have the opportunity to scrap a junked one of these as aluminum is usually five times the price or more than scrap steel.
One thing that hurts you at the scrap yard is when different metals are “mixed” such as in an engine block. Even if you strip the bearings, crank/cam, pistons, and such from an aluminum block, there are still cylinder sleeves and other inserts to deal with. I know a guy who quarters up old engine blocks with a sawzall and the sleeve parts just fall right out of the cylinders. This is done to increase the scrap value from not much more than steel to 5x that of steel. I don’t know if this effort is worthwhile given the time required but he does it.
