Pratt & Whitney recently started flight tests of its PurePower PW1200G engine family with the PW1217G engine for the Mitsubishi Regional Jet (MRJ) aircraft. Like other engines in the PurePower Geared Turbofan engine program, the PW1217G's fan blades incorporate titanium, not composites. (Source: Pratt & Whitney)
@Ann: Thanks for this article. It would be interesting to know more about the composition of the hybrid metallic blade, although I'm sure that since it's a proprietary design, Pratt and Whitney may not be forthcoming with the details. From what I've read on some other websites, the blade is made from a composite, but has a titanium leading edge, along with metallic cross-ply reinforcement. (This is why it's called a "hybrid"). Interestingly enough, this is something that Pratt and Whitney has been working on since the 1970s.
Dave, I also wish we could have gotten more detail about the nature of the hybrid metallic material. Like those other sources, we do mention here that the blade has a titanium leading edge. It's possible that "hybrid metallic" means including plastic composites, but from what I've seen, that term can also mean metal-plus-ceramic, or multiple metals, or some combination of the above.
It's still just a guess that the composites are woven or even that they include fiber; that's not been verified. It's worth considering, though, that composites have been used for wind turbine blades, although the stresses involved are obviously quite different.
The implementation of a new diesel fuel standard in the US has considerably improved the environmental performance of diesel vehicles. The Environmental Protection Agency (EPA) says that the new ultra-low sulfur diesel (ULSD) fuel has combined with other improved technologies to reduce diesel's particulate matter (PM) emissions by 99%.
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.