What are the properties of cubic boron nitride?

What are the properties of cubic boron nitride?

Cubic boron nitride (c-BN) has a cubic structure and extraordinary properties, including low density (2.51 g·cm−3); exceptional hardness (HV >45 GPa), fracture toughness (KIC >12 MPa·m1/2) and thermal conductivity (760 W·m−1K−1); high temperature resistance (TM >2950°C [inert atm.])

What is polycrystalline cubic boron nitride?

Polycrystalline cubic boron nitride (PcBN) is the second hardest material in the world; only diamond is harder. The extensive range of PcBN high-performance cutting materials from CeramTec enables reliable HPC machining of gray cast iron workpieces.

How strong is cubic boron nitride?

6.8. 5.4 Boron Nitride and Carbon Nitride. Bulk cubic boron nitride (c-BN) is also a remarkable material. It has a hardness (70 GPa) second only to that of diamond (100 GPa), and its thermal conductivity, at half the diamond value, is still very high.

Is cubic boron nitride brittle?

The cubic (zincblende aka sphalerite structure) variety analogous to diamond is called c-BN; it is softer than diamond, but its thermal and chemical stability is superior. The rare wurtzite BN modification is similar to lonsdaleite but slightly softer than the cubic form….Boron nitride.

What is CBN Cutting Tool?

CBN tools are used for machining hardened steels because they offer a cost-effective alternative to grinding processes. Further applications are machining of cast iron and gray cast iron as well as cold and hot work steels. CBN is also increasingly used for machining of super alloys (nickel and cobalt alloys).

Why is cubic boron nitride so hard?

Manufacturing c-BN Boron Nitride (in its hexagonal form, h-BN) goes under high heat and pressure, without hitting the melting point, to create a solid mass.

Is boron nitride stronger than diamond?

But cubic boron nitride is still, at best, just the world’s second hardest material with a Vickers hardness of around 50 GPa. Its hexagonal form (w-BN) was initially reported to be even harder but these results were based upon theoretical simulations that predicted an indentation strength 18% higher than diamond.

What is cubic boron nitride used for?

Cubic boron nitride is also a desirable material for electronic applications due to its wide band gap, insulating properties, and high thermal conductivity. It is used as a heat sink in semiconductor lasers, microwave devices, and LEDs. Furthermore, Si or Be doped c-BN can be utilized as p-n junction diodes.

Can you grind carbide with CBN?

About grinding Carbide with CBN: CBN is a superabrasive and will grind cemented carbide. To sum up, CBN and Carbide products vary considerably in quality/hardness With a good wheel and average carbide (which is usually the case) intermittent use it can be done, but physics with eventually catch up wear out the wheel.

Is CBN harder than ceramic?

Because cBN is harder than any Al 2O 3 or ceramic grain, a grinding machine needs to be rigid enough to withstand the grinding forces.

Is Cubic Boron Nitride harder than diamond?

What is the toughest material on earth?

Diamond
Diamond is the hardest known material to date, with a Vickers hardness in the range of 70–150 GPa. Diamond demonstrates both high thermal conductivity and electrically insulating properties, and much attention has been put into finding practical applications of this material.

What does CBN grinding stand for?

Cubic boron nitride
Cubic boron nitride (CBN) is a highly durable synthetic abrasive mineral, second only to diamond in hardness. This durability makes it ideal for grinding hardened steel and superalloys – materials commonly used in the manufacturing of powertrain, bearing and turbine components.