Zirconium carbide

• Zirconium (IV) carbide
• Zirconiummonocarbid

Odorless gray solid

Fixed

6.73 g · cm -3

3540 ° C

5100 ° C

Insoluble in water

Attention

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Zirconium is an inorganic chemical compound from the group of carbides.

Production and representation

Zirconium carbide may be represented by the same procedures as titanium carbide. It can be obtained by carbothermal reduction of zirconia

Be obtained or by synthesis from the elements at more than 2000 ° C. Since zirconium is very sensitive to nitrogen, necessary to work at the Hochsinterung with very pure argon. In the reactions should be noted that carbon dissolves in zirconium carbide, with its melting point is lowered to 3100 ° C. When cooled, the carbon precipitates again.

It can also be displayed from zirconium ( IV) chloride.

Also possible is the production by plasma CVD.

Properties

Zirconium carbide is an odorless gray powder that is practically insoluble in water. It is insoluble in hydrochloric acid and sulfuric acid, but is soluble in nitric acid. It is stable in air up to 800 ° C. Zirconium carbide has a crystal structure of the sodium chloride type with considerable phase width ( ZrC0 ,99 - ZrC0, 55). It has a Vickers hardness of 25.5 GPa and a modulus of 350-440 GPa. With halogens Tetrahalide it forms at temperatures above 250 ° C. As titanium carbide forms with oxygen and nitrogen solid solutions.

Use

Zirconium is in contrast to titanium carbide used in spite of its good properties for coatings of fuels from nuclear and fusion reactors. The reason is possibly the high price and the difficulty to free it from impurities.