Talk:Tantalum hafnium carbide

Properties
What are other properties of this material, such as hardness at high temperature? Where to get such information? — Preceding unsigned comment added by 66.212.144.205 (talk) 03:54, 12 February 2008‎

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It seems that the final sentence in this Properties section needs updating. The Hf-C-N melting point has now been confirmed by experiment.

See: Buinevich, V.S.; Nepapushev, A.A.; Moskovskikh, D.O.; Trusov, G.V.; Kuskov, K.V.; Vadchenko, S.G.; Rogachev, A.S.; Mukasyan, A.S. (March 2020). "Fabrication of ultra-high-temperature nonstoichiometric hafnium carbonitride via combustion synthesis and spark plasma sintering". Ceramics International. 46 (10): 16068–16073. doi:10.1016/j.ceramint.2020.03.158. S2CID 216437833.

With apologies; I don't know how to post this information correctly on the Article page, so have presented it here, so that someone with more experience can verify it, post it correctly, and then delete the comments in this section.

The information is copied and pasted from the Wikipedia article 'Melting Point'.

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Any more info?
This article seems pretty short. Does it have any uses? Is there any more info on it, like when it was discovered? —Preceding unsigned comment added by 70.216.49.55 (talk • contribs) --Leyo 08:30, 29 August 2008 (UTC)

Formula
The article gives the formula for THC(!) as formula TaxHf1-xCy, which seems to imply that if there are 3 atoms of Tantalum, there should be (1-3 =)&minus;2 atoms of hafnium, an ovbious impossibility. The article then goes on to describe an "alloy" whose formula doesn't match the first one, either. Should that first formula read "TaxHfyCz, where z = x + y"? Something else? --Piledhigheranddeeper (talk) 20:19, 6 May 2011 (UTC)

I would believe this is just a typo and the formula was intended to be written as TaxHfy-xCy --Kaomie —Preceding unsigned comment added by 68.227.207.20 (talk) 22:15, 6 May 2011 (UTC)
 * Not a typo but a convention (x is not an integer but is less than 1). It is often used to mean that Ta+Hf=1, though I admit this is irrelevant here because y is variable (though <1). Materialscientist (talk) 01:41, 7 May 2011 (UTC)

Temperatures
I don't get it: how is it that the "highest melting point for any solid" (3,942 °C for Ta4HfC5) is lower than melting point of one of the component? ( tantalum carbide 3,983 °C). Also, all the wikipedia in other languages report a melting temperature of 4 215 °C for the alloy. And in his own page the english wikipedia report a value around 3800°C for the pure tantalum carbide. It seems there is a little bit of confusion about this temperatures — Preceding unsigned comment added by 151.33.107.165 (talk) 00:03, 2 August 2015 (UTC)


 * You're correct, the 1930 value is indeed quite suspect. There have been more recent and likely more accurate values reported since then. I've updated the article to include these. Ezrado (talk) 13:02, 4 August 2015 (UTC)

Incorrect Optimal Oxidation Resistant Composition
The 1965 article by Deadmore incorrectly cites the optimal oxidation resistant composition from the 1960 study by Engelke et al., who do not claim it is the optimal composition, only that it is higher than those of HfC and TaC. The most recent experiments showed that a 3 HfC : 1 TaC composition currently has the optimal oxidation resistance. (See J. Zhang, S. Wang, W. Li, Y. Yu, and J. Jiang, “Understanding the oxidation behavior of Ta–Hf–C ternary ceramics at high temperature,” Corros. Sci., vol. 164, 108348, 2020) 199.111.226.218 (talk) 20:50, 1 November 2023 (UTC)