So is this why Gen IV delayed?

Granted, aluminum is more expensive than steel, but a crude cost-benefit analysis reveals many benefits of aluminum outweighing the cost. Weight is always a liability against fuel economy, and corrosion-resistance is a no-brainer. How many car-owners have abandoned a brand entirely because of premature rusting-out? Why should any vehicle rust out?

 

Both materials have advantages and disadvantages.

I's cost effectiveness and design life.

While long life is possible with aluminum, there is costs and reparability.

Steel is used, because it is strong, inexpensive and easy to repair.

Aluminum, while long lasting, is tough to form, hard to fasten and difficult to finish and paint effectively.

The design life of an automobile is limited, basically to 10 years and 150k-200K miles.

Anything beyond that is an extra benefit.

 

Not to nit-pick, but aluminum airplanes seem to last almost forever; until they crash or no longer have parts available. They last for decades, and seem to be infinitely repairable. I understand that aluminum is harder to repair and paint, but great strides have been made in those directions in recent years.

I think the biggest required change will be the mind-set.

 

"Seem" is a call apparently not based on fact.

I've been involved with aluminum used in the construction and repair of aluminum for over 35 years.

Yes, aluminum, if left in the environment might appear to last forever.

In service, it is, however, not true.

The classic study of aluminum in aircraft has to be the De Havilland Comet.

Duralumin or aluminum alloys have characteristics that need special consideration in construction.

Any aluminum alloy made stronger is under high stress that subjects it to vibrational and stress corrosion cracking.

Pressurizing and depressurizing aluminum alloys, even to a low percentage of it's yield strength, will cause aluminum crystals to develop separations from itself and other alloying elements.

With the exception of rusting, steel is not subject to low level fatigue.

The only reason steel is not used more widely in aircraft is it's weight. There is, however, a lot of steel in aircraft, where aluminum just is not strong enough.

As cars are concerned, most car frames will still be made of steel.

 

Is your "De Havilland Comet" reference to do with the spate of crashes in the early 1950s? I believe the cause was eventually traced to the cockpit windows which failed under pressurization, not to any structural failure of the aluminum.

Do cars still use frames? I believe the trucks all still do, and some new Ford trucks are using aluminum bodies. I believe the Corvette had problems with aluminum frames cracking at one time.

I believe I read somewhere that an aluminum beverage can takes thousands of years to decompose.

 

Wood was the original material for frames and car bodies.

Aluminum originally competed with steel and wood. Most cars prior to 1930 had a lot of wood in them.

Automobile Chassis History

Aluminum in the environment will last a long time. Buried in a desert alkali soil, to will be eaten away sooner than later.