"Glass" Metals for Gas Turbines?

According to _Science News_ new alloys allow for an amorphous, no crystal structure, "glass" metals much harder and stronger than conventional metals.
Are these alloys also more heat resistant? Would they make good turbine nozzles or buckets?
Bret Cahill
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BretCahill wrote:

Give numbers, please.

man 'crystallization'
Michael Dahms
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See: Ryusuke Hasegawa: "Glassy metals: magnetic, chemical and structural properties". CRC Press, 1983, 280pp.
p. 189: "Characteristic values (of the elastic limit) for Fe-Ni and Co-based metallic glasses range from 2000 to 2500 N/mmsq. Typical values of Young's modulus are 150 kN/mmsq for the same group of alloys. This means that they can be subjected to four to five times the stresses and elastic strains that can be sustained by crystalline Fe-Ni-based soft magnetic materials without plastic deformation and have correspondingly high hardness."
J.J.

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jacques jedwab wrote:

2000 to 2500 MPa UTS ist strong. But if they don't show sufficient elongation to failure, their use for structural applications is limited. For gas turbines, creep-resistance is necessary.
A relatively low modulus of 150 GPa is useful for elastric-strain-dominated applications.
If the material ist compared to "Fe-Ni-based soft magnetic materials", it is probably not aimed as a structural material.
Michael Dahms
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I once heard some turbine blades were single crystals.
Michael Dahms snipped-for-privacy@gkss.de in

Even if there are no tip clearance problems?
Bret Cahill
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BretCahill wrote:

It's common knowledge. 'single crystal' is the antagonist to 'glass'.

Yes. man 'creep rupture'
Michael Dahms
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Amorphous materials are made when they're cooled too quickly for the atoms to arrange themselves into crystals. Raising the temperature increases the mobility of the atoms. If you use it in high temperature applications, it won't stay amorphous very long.
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Speaking of turbines, since you bring it up, thermal barrier coatings are used on turbines to increase their operating temperature. But one thing I'm not clear on is that when it's running for a while, TBC or not, those blades are going to heat up anyway unless they're continually shedding heat. How do they do that? Conduction through the blades to a cooled hub?
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"Gregory L. Hansen" wrote:

Try Google on "cooling channels" and "turbine blade". There are internal passages through which cool gas flows.
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Mark Thorson snipped-for-privacy@sonic.net in

And then it flows out into the combustion gas amounting to negative reheat.
It's 25% of the compressor output in some engines so higher temperatures must really be worth it.
Bret Cahill
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BretCahill wrote:

Common knowledge for heat engines..... seeking the highest operating temperature for maximum extraction of work from a given amount of fuel.
It helps to remember thermodynamics, sometimes. Understanding is quite good too.
Jim
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Wow, that looks expensive.
I'm a little bit surprised at how much one can read about thermal barrier coatings on turbine blades without seeing any mention of the cooling process.
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snipped-for-privacy@steel.ucs.indiana.edu (Gregory L. Hansen) in

Kerosene by now must be 80 - 85% of the cost of air travel.
A 50 MW aircraft engine is pretty cheap on a dollar/hp basis as well as on a engine cost/ fuel cost basis.
Some NASA engineer said 60% of the R & D cost of gas turbines was materials.

They may reflect some heat.

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Gregory L. Hansen wrote:

That seems to be a tradition. No overview of how this thermal barrier coating stuff works in a system, and it is probably assumed that anybody interested in these barrier coatings already knows why and how they work.
Remembering back to my first exposure to the field. They make little sense until their role in cooling is explained. So, there is a long tradition of this.
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