@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.
At this year's MD&M West show, lots of material suppliers are talking about new formulations for wearables and things that stick to the skin, whether it's adhesives, wound dressings, skin patches and other drug delivery devices, or medical electronics.
Researchers at Lawrence Livermore National Laboratory have published two physics-based models for the selective laser melting (SLM) metals additive manufacturing process, so engineers can understand how it works at the powder and scales, and develop better parts with less trial and error.
Materials and assembly methods on exhibit at next week's MD&M West and other co-located shows will include some materials you should see, as well as several new and improved processes. Here's a sampling of what you can expect.
The Food & Drug Administration has approved a 3D-printed, titanium, cranial/craniofacial patient-specific plate implant for use in the US. The implant is 3D printed using Arcam's electron beam melting (EBM) process.
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