Ultra High Temperature Corrosion Resistant Alloys

Maybe this will help...

http://www.hpalloy.com/Alloys/hightemperature.aspx

http://www.haynesintl.com/tech-briefs/high-temperature-alloys/high-temperature-alloy-applications/high-temperature-alloys-for-industrial-applications-(H-3116)

Thanks

Titanium melts at 1680° C. Something is wrong here. Pure Tungsten melts at 3414° C but any pure metal at these temperatures in air will oxidize. This is why filament lamp bulbs are filled with an inert gas, usually simple Nitrogen gas.

If you must operate at 3000° C in air then ultra high temperature ceramics are your field to explore. There you will find some Titanium compounds that can withstand these temperatures.

Thanks we plan to encase the burners with Argon gas but also will explore whether using ceramics is better as well as costings for both ceramics and tungsten

Wow! that's really hot...what prey-tell is the application?

..."Tantalum carbide (TaC) and hafnium carbide (HfC) are refractory ceramics, meaning they are extraordinarily resistant to heat. Their ability to withstand extremely harsh environments means that refractory ceramics could be used in thermal protection systems on high-speed vehicles and as fuel cladding in the super-heated environments of nuclear reactors. However, there hasn’t been the technology available to test the melting point of TaC and HfC in the lab to determine how truly extreme an environment they could function in.

The researchers of the study, which is published in the journal Scientific Reports, developed a new extreme heating technique using lasers to test the heat tolerance of TaC and HfC. They used the laser-heating techniques to find the point at which TaC and HfC melted, both separately and as mixed compositions of both.

They found that the mixed compound (Ta0.8Hf0.20C) was consistent with previous research, melting at 3905°C, but the two compounds on their own exceeded previous recorded melting points. The compound TaC melted at 3768°C and HfC melted at 3958°C."...

I would use a sintering process to coat your tungsten pipes...

..."Tantalum carbide is widely used as sintering additive in ultra-high temperature ceramics (UHTCs) or as a ceramic reinforcement in high-entropy alloys (HEAs) due to its excellent physical properties in melting point, hardness, elastic modulus, thermal conductivity, thermal shock resistance, and chemical stability, which ..."

Not cheap...

In a separate study, Ta₄HfC₅ was found to have the minimum oxidation rate among the TaC-HfC solid solutions.^[4] Ta₄HfC₅ was manufactured by Goodfellow company as a 45 µm powder^[5] at a price of $9,540/kg (99.0% purity).^[6]

https://en.wikipedia.org/wiki/Tantalum_hafnium_carbide

https://www.imperial.ac.uk/news/176628/new-record-worlds-most-heat-resistant/

Thanks for your detailed reply we are thinking about ceramics as well. The Tungsten tubes we use must handle 3000 C as we are using Hydroxy gas (known as Browns Gas) from conventional electrolysis and it burns on application at 3000 C. We are planning to encapsulate the burners in Argon gas to help prevent oxidation but if there is a better alternative to Tungsten then we will explore that R&D does cost time and money.

..."Oxyhydrogen is a mixture of hydrogen (H₂) and oxygen (O₂) gases. This gaseous mixture is used for torches to process refractory materials and was the first^[1] gaseous mixture used for welding. Theoretically, a ratio of 2:1 hydrogen:oxygen is enough to achieve maximum efficiency; in practice a ratio 4:1 or 5:1 is needed to avoid an oxidizing flame.^[2]

This mixture may also be referred to as Knallgas (Scandinavian and German Knallgas: "bang-gas"), although some authors define knallgas to be a generic term for the mixture of fuel with the precise amount of oxygen required for complete combustion, thus 2:1 oxyhydrogen would be called "hydrogen-knallgas".^[3]

"Brown's gas" and HHO are terms for oxyhydrogen mainly encountered in fringe science.^[4] "...

..."The maximum temperature of about 2,800 °C (5,100 °F) is achieved with an exact stoichiometric mixture, ..."...

https://en.wikipedia.org/wiki/Oxyhydrogen

Making gemstones....?

https://en.wikipedia.org/wiki/Verneuil_method

No but that's a good idea for an application of our technology down the track I'll run it by my colleagues thanks.

Regarding how to achieve temperatures high enough to test these melting points---

I read about 15 years ago that when Uranium burns, its flame temperature is well over 4000 °C. However, I cannot conceive of any safe way that this material and the resulting products of the flame can be used for such purposes.

--JMM

What is your application?What is the maximum temperature/pressure of the process?

Iridium is very resistant to corrosion,better than platinum or gold,and has fairly high melting point,but not as high as some alloys.

It is used in high-end spark plugs,for instance.

Your question implies a need for corrosion resistance rather than strictly high temperature tolerance.

More info would certainly help.

Thanks for your reply I cant elaborate too much as we are finalising Patent applications but with Hydroxy gas from electrolysis it burns at 3000 C on application but can cause oxidation of the Tungsten so we are also thinking of using Ceramics instead of Tungsten as they are oxidation resistant.

What's the application exactly, some sort of small lab experiment or some large scale industrial process?

What is it being used for exactly?

How large and what shape?

Hi thanks for your reply a few posts have suggested to use Ceramics which we are considering as we use Hydroxy gas from electrolysis which burns at 3000 C on application that's why we need the Tungsten it will be for a large scale industrial process but as we are finalising Patent applications I cant elaborate on it.