@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.
Last week, the bill for reforming chemical regulation, the TSCA Modernization Act of 2015, passed the House. If it or a similar bill becomes law, the effects on cost and availability of adhesives and plastics incorporating these substances are not yet clear.
The latest crop of coating and sealant materials and devices has impressive credentials. Many are designed for tough environments with broad operating temperature ranges, and they often cure faster, require fewer process steps, and produce less waste.
A new program has been proposed for testing and certify 3D printing filaments for emissions safety. To engineers who've used 3D printers at home this is a no-brainer. It's from a consumer on Kickstarter, and targets use in homes and schools.
For the last 50 years, the Metal Powder Industries Federation (MPIF) has sponsored an awards competition for creative solutions to designing and fabricating near-net-shape parts using powder metal (PM) technologies. Here are the seven Grand Prize winners of the 2015 contest.
Graphene 3D Lab has added graphene to 3DP PLA filament to strengthen the material and add conductivity to prints made with it. The material can be used to 3D print conductive traces embedded in 3D-printed parts for electronics, as well as capacitive touch sensors.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.