Metal rockets might come back into favour?

[satamax]

Well, someone on the barrel discussion at permies, spoke of furnace elements in molybdenium.

www.alibaba.com/product-detail/Molybdenum-Heated-barrel-in-high-temperature_964649189.html

Looking at the properties, it seems ideal, sort of. en.wikipedia.org/wiki/Molybdenum

Tougher than steel, high melting point. Easily-ish bendable. Not too subject to oxidizing.

So i had a look if i could find sheet molybdenum.

There's some existing.

www.plansee-express.com/EN/category/PLANSEE%20EXPRESS/Molybdenum%20and%20alloys/Sheet%20≥%200-61mm%20thickness/Standardised%20Articles

And, with something like 0.3mm thick, we could roll our own pipes. Held by steel wire on the outside. It's just the "elbows" of a J tube which i would have to imagine how to do.

Now, the hard part is finding the price!

[Deleted]

www.plansee-express.com/EN/category/PLANSEE%20EXPRESS/Molybdenum%20and%20alloys

[Deleted]

Likely a lot cheaper

Quote:
In addition, further heating of MK based geopolymer coating with flame torch (temperature
between about 1100oC-1200oC) has proved that mild steel coated with MK is very stable during
heating and cooling.

Reviews on the Geopolymer Materials for Coating Application
www.researchgate.net/profile/Zarina_Yahya/publication/256378677_Reviews_on_the_Geopolymer_Materials_for_Coating_Application/file/3deec5226d9671b7f7.pdf

[Daryl]

Did metal rockets ever fall out of favor? Missed that one.

[photoman290]

Jun 29, 2014 3:35:33 GMT -8 @karl said:

Likely a lot cheaper

Quote:
In addition, further heating of MK based geopolymer coating with flame torch (temperature
between about 1100oC-1200oC) has proved that mild steel coated with MK is very stable during
heating and cooling.

Reviews on the Geopolymer Materials for Coating Application
www.researchgate.net/profile/Zarina_Yahya/publication/256378677_Reviews_on_the_Geopolymer_Materials_for_Coating_Application/file/3deec5226d9671b7f7.pdf

from a quick scan of that paper it looks like  you could coat the inside of MS tubing by just pouring a slurry of geopolymer into the tube rolling the slurry around inside to coat it all over and pouring it out. it looks like to get it to bond to the steel may need to be really clean. they washed it in acetone after cleaning it with sandpaper and maybe wire wool? it only needs a thin coating less than 1 mm. certainly worth a try.

[photoman290]

another paper,not directly related but free, and may have some useful info on coating methods and durability.
cait.rutgers.edu/files/FHWA-NJ-2002-011.pdf

i am still trying to find a free copy of some of the links on the paper karl qouted. temuujin seems it have done a lot of work in the area we could interested in. a metal rocket with a burn tube made from standard tubing with a bend to the riser coated with geopolymer slurry sounds doable and cheap enough for an experiment.

[Robert]

there are some strange things going on with those polymer thingy... if i could just understand english better

Karl is there any possibility that you make some photos with simple explanations?

Photoman and if you make some experiment can you make pictures, videos?

Thos polymers are driving me crazy looks like it is an interesting thing...

[photoman290]

as soon as i get time i intend to do some tests and will will do pictures of the results.

[Deleted]

Jul 9, 2014 15:20:09 GMT -8 Robert said:

Karl is there any possibility that you make some photos with simple explanations?

I have just mixed some powders with water.

There are lots of videos at YouTube

Geopolymer Ceramic mixing
www.youtube.com/watch?v=U_8JdPyysMc

Geopolymer Ecological Cement mixing
www.youtube.com/watch?v=PQZx7PSol1E

Mixing geopolymer at CCHRC
www.youtube.com/watch?v=zS5lK7DdmYU

Geopolymer/ Garage apron pour at CCHRC
www.youtube.com/watch?v=k8AbCRF_OTE

Fire proof and thermal transfer blocking coating
www.youtube.com/watch?v=vh6ofLmMdYc

Geopolymer/fiber board
www.youtube.com/watch?v=YKMiHnVyC0U

geopolymer vs oxyfuel.wmv
www.youtube.com/watch?v=37v7EuXwBXA

[satamax]

So, back to metal.

Some people on an engineering site told me that the molybdenum oxydizes like crazy, and is no good.

And one suggested this

www.kanthal.com/en/products/material-datasheets/tube/kanthal-apmt/