http://sakimori.nims.go.jp/documents/990225b.html was the first one; the interesting bit of data is figure 1. MarM247, sitting there quite a long way under the red iridium-based lines, is a current best-available turbine-blade alloy.
http://sakimori.nims.go.jp/documents/001113a.html investigates four-element alloys, though the character-set information has been slightly mangled; http://nippon.zaidan.info/seikabutsu/2003/00916/pdf/igtc2003tokyo_ks2.pdf is a large but interesting overview article.
OK, there are some small pricing issues associated with making the blades for jet engine or power station turbines out of materials slightly more costly than platinum, but the design and machining costs are themselves large enough that even that class of material cost is not insuperable, particularly since a 500MW turbine produces electricity with a retail value of about a hundred thousand pounds per hour of operation and consumes, at the 33% thermal efficiency of Drax, 1200 tonsworth of CO2-emission permits which at one point cost 30 euros the tonsworth: that iridium is twice as dense as lead does make things a bit awkward, but increasing thermal efficiency significantly, so substantially reducing the weight of CO2-emission permits that you are burning an hour, might well be enough to break even.
What surprises me slightly is that all this research is in Japan, whilst if asked to name four jet engine manufacturers I'd list Rolls-Royce, General Electric, Pratt and Whitney, and then confess myself lost and try to Google up who Sukhoi and MIG's suppliers are. I suppose there are quite a lot of power stations in Japan, mostly built by Japanese companies, and that this has built up expertise such that the turbines in power stations worldwide may well be bought from Hitachi.