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Boride character table

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  TiB2 ZrB2 TaB2 NbB2 WB MoB CrB LaB6
Boron content[%] 31.11 19.16 10.67 18.88 5.55 10.13 17.21 31.83
Crystal structure Hexagonal Hexagonal Hexagonal Hexagonal Tetragonal Tetragonal Orthorhombic Cubic
Lattice periods,kx. a 3.026 3.168 3.078 3.089 3.115 3.110 2.969 4.1561
b or c 3.213 3.528 3.265 3.303 16.93 16.97 b 7.858 C 3.002  
c/a 1.062 1.114 1.050 1.060 5.42 5.45    
Density[g/cm3]
calculated		 4.530 6.09 12.62 7.00 15.734 8.665 6.11 4.722
experimental 4.38 6.17 12.38 6.97 〜15.4 8.3 6.05 4.76
Microhardness 30g
[kg/mm2]		 3370±60 2252±22 2500±42 2600 3700(50g) 2350(50g) 〜1300(100g) 2770±60
Melting Point[℃] 2790 3200 3037 3000 2800 2550 2100 2530
Heat of formation
ΔH°(298）[Kcal/mol]		 -70 -76.7 -46 -59.00 -17 -16.3 (CrB2) -30 -112.3
Entropy S°(298)
[Kcal/mol・℃]		 7.52 10.7 13.9 10.4     5.8  
Specific electrical
resistance[μΩ cm] at
20℃		 9.0 9.7 32.5 25.7 〜22 45 45.5 15.0
Point of transition to
superconductivity °K		 <1.28 <1.80 <1.28 <1.0 <1.28 <1.28 <1.28 5.7

(Reference) Hand book refractory compounds (metallurgiya in Moscow 1976 editions)

 

Metallic boride compound powders are very important ingredients for functional new ceramic materials. The company is actively developing a variety of new heat-resistant and hard materials that can be accurately finished using electric discharge machining to product materials with high melting points, high hardness, good electrical conductivity, and good thermal conductivity.
TiB2 is mainly used in ultra-hard materials but is also used in Al molten metal related corrosion-resistant materials and deposition boards.
ZrB2 is also an excellent hard material and its properties are utilized heat-resistant ceramics, especially fire-proof materials used for steel production.Products for various applications have been organized into three product categories. CrB and CrB2 have better oxidation resistance than other boride compounds and so are used to improve the Purity of refractories as heat-resistant coatings. MoB and WB are important as hard materials, and also are important ingredients in iron and nickel boride compound cermet materials.
LaB6 is used as a thermoelectronic emission material in the displays of plasma displays and applications for use in a variety of cathode materials are being developed. Boride compounds are very unstable over time, and in particular are oxidized by moisture in the air, which increases the oxygen and moisture content.

 

 

 

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