Difference between revisions of "Simple metal containing carbides and nitrides"

Revision as of 18:35, 1 July 2021

There are few/no natural mineral examples for these compounds.
This is likely because all these compounds are in a highly reduced stated and some of them are
not even capable of forming a protective macroscale passivation layer.

Awesome compounds

Titanium:

• TiC Titanium carbide – and ZrC Zirconum carbide
• TiN Titanium nitride

Silicon (counting silicon as metal here):

• SiC Silicon carbide
• Si₃N₄ Silicon nitride [1]

For more awesome compounds see: Base materials with high potential

Compounds that need to be sealed in PPV to be usable

Iron:

• Fe₃C Iron carbide aka cementite aka iron cohenite – ortorhombic – Mohs 5.5 to 6.0 – 7.20 to 7.65g/ccm – metallic luster
• Iron nitrides – Wikipedia: "Group 7 and group 8 transition metals form nitrides that decompose at relatively low temperatures" Fe₂N 400°C

Aluminum:

• Al₄C₃ Aluminum carbide [2] – hydrolyses in contact with water
• AlN [3] – hydrolyses in contact with water – it's a diamond like compound (a III-VI semiconductor) – highly covalent character

Calcium:

• CaC₂ Calcium carbide [4] – must be kept dry – releases ethyne on contact with water
• Ca₃N₂ calcium nitride [5] – highly reactive with water

Magnesium:

• Mg₃N_2(s) Magnesium nitide [6] – reacts with water
• Magnesium carbide ??

Compounds with more rare elements

Nitrides:

• CrN – Carlsbergite (mineralienatlas) – Mohs 7
• VN – Uakitite – Mohs ??

• ZrN – Zirconium nitride
• NbN – Niobium nitride – 2573°C – 8.47g/ccm
• MoN (and Mo₂N) – Molybdenium nitride (?)

• (W₂N, WN, WN₂)Tungsten nitride – unstable against water
• HfC – Hafnium carbide – refractory compound
• TaN (anf other stoichometries) – Tantalum nitride

Carbides:

4th period:

• Cr₃C₂ – Tongbaite (wikipedia (mineralienatlas) – Mohs 8.5 – ortorhombic
• Various chromium carbides: Chromium(II) carbide
• Cr₃C₂; Cr₇C₃; Cr₂₃C₆ (1,895 °C; 3,443 °F; 2,168 K; extremely hard; very corrosion resistant)
• VC (2810 °C; 9-9.5 Mohs, cubic)

5th period:

• ZrC (3532 °C; extremely hard; highly corrosion resistant; very metallic, cubic)
• Nb₂C (3490 °C; extremely hard; highly corrosion resistant)
• Mo₂C (2692 °C) [7]; MoC; Mo₃C₂ [8]

6th period:

• HfC (3900 °C; very refractory; low oxidation resistance, cubic)
• TaC – Tantalum carbide (mineralienatlas) – Mohs 6-7 – tantal is very rare
• WC – Qusongit (mineralienatlas) – Mohs 7.25

Borides:

4th period:

• CrB (and other stoichometries Cr₂B, Cr₅B₃, Cr₃B₄, CrB₂, and CrB₄) – Chromium(III) boride – refractory 2100°C – very hard
• VB, VB₂ – Vanadium boride (?)

5th period:

• Zr₂ – Zirconium diboride
• Nb₂ – Niobium diboride
• Molybdenium boride ??

6th period:

• Hf₂ – Hafnium diboride
• Ta₂ – Tantalum boride
• WB₂ (WB, WB₄) – Tungsten borides
• ReB₂ Rhenium_diboride
• OsB, Os₂B₃ and OsB₂ – Osmium borides

Related

• Refractory compound

External links

• Superhard material
• Category:Superhard_materials