Large cubic boron nitride compacts.(MATERIALS)

Showa Denko KK, Japan, has developed what it claims is the world's largest sintered compacts of cubic boron nitride (CBN).

Conventional CBN sintered compacts generally measure up to 5 mm in thickness, whereas SDK's versions can be provided in thicknesses of 0.5-12 mm for a 29 mm diameter disc and 0.8-20 mm for a 60 mm diameter disc.

The compacts are designed for machining automotive parts, including engine cylinders and brake discs.

CBN is the hardest substance next to diamond, and it also has high corrosion resistance and does not react chemically with iron. Therefore, the material is used mainly in tools for processing steel.

So far, small chips of sintered CBN have been used as tips for cutting tools. With the development of large sintered compacts, CBN is expected to find additional applications, in such rotating tools as end mills, drills and reamers, SDK predicts.

Demand for CBN-based cutting tools is expected to grow at an annual rate of 8%, due to the expansion of automobile production in China and south-east Asian countries, allied to the expected shift from traditional grinding processes to cutting processes. Although grinding is still the most common method of machining steel components, it suffers from problems with regard to disposal of grinding fluid waste, and there are also operational efficiency issues.

Demand for sintered compacts of CBN is expected to grow accordingly, with the size of the world market forecast to expand from [yen] 5.5 billion (about $40 million) at present to more than [yen] 8 billion (about $67 million) by 2010.

SDK is aiming to achieve annual sales for CBN sintered compacts of [yen] 1 billion (about $8 million) in 2010, including the newly developed large-sized products.

For further information, contact: Marketing Department I, Ceramics Division, Showa Denko KK, 1-13-9, Shiba-Daimon, Minato-ku, Tokyo 105-8518, Japan; tel: +81-4-5453-5110; fax: +81-3-3431-6442; E-mail: nobuhiro_kato@sdk.co.jp; Internet: www.sdk.jp; or: Showa Denko (Europe) GmbH, Unlandstrasse 9, D-40237 Dusseldorf, Germany; tel: +49-211-684035; fax: +49-211-6798-665.