@Ann: Although steel is stronger than aluminum, it's not really too surprising that forged aluminum wheels are stronger than steel wheels made from sheet metal -- the designs and manufacturing processes are completely different. A forged steel wheel would be much stronger than a forged aluminum wheel, but would also weigh a lot more. (Forged steel wheels make sense for railroad cars, but definitely not for on-road applications).
The lifecycle analysis is very interesting. It is very comprehensive, and all of the assumptions seem to be reasonable. It makes a convincing case.
Lou, you're certainly right about the recyclability of aluminum, and steel too to a somewhat lesser extent. But it's also true that LCA has to look at everything. In fact, the latest concept of the life cycle is "cradle-to-cradle", not "cradle-to-grave." CtoC includes that last link in the chain that closes the loop (to mix metaphors) of recycled material going back into the product.
Ann, you mention end of life phases when talking about the life cycle cost analysis. You mention recycling and disposal. Steel and aluminum of this type will certainly be recycled. It has been known for some time that aluminum recycling is extremely effecient. I think it uses about 5% of the energy to recycle aluminum as it does to refine it from bauxite. Steel is also effecient, although I am not sure of the ratio. Steel mini-mills are the most effecient steel mills becuase they use scrap. So, I assume in this case the wheels of both types will be recycled.
It is good, though to see such comprehensive analysis. If you are looking at full lifecycle costs, then you really have to look at everything.
The 100-percent solar-powered Solar Impulse plane flies on a piloted, cross-country flight this summer over the US as a prelude to the longer, round-the-world flight by its successor aircraft planned for 2015.
GE Aviation expects to chop off about 25 percent of the total 3D printing time of metallic production components for its LEAP Turbofan engine, using in-process inspection. That's pretty amazing, considering how slow additive manufacturing (AM) build times usually are.
For industrial control applications, or even a simple assembly line, that machine can go almost 24/7 without a break. But what happens when the task is a little more complex? That’s where the “smart” machine would come in. The smart machine is one that has some simple (or complex in some cases) processing capability to be able to adapt to changing conditions. Such machines are suited for a host of applications, including automotive, aerospace, defense, medical, computers and electronics, telecommunications, consumer goods, and so on. This radio show will show what’s possible with smart machines, and what tradeoffs need to be made to implement such a solution.