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KYOCERA Introduces New Cutting Tool Inserts in MEGACOAT CBN Series

Industry-first cell fiber structure, new materials double life, increase productivity

October 23, 2008
Kyocera Corporation (President: Makoto Kawamura) announced that its Cutting Tool Division has developed the MEGACOAT CBN KBN35M, a cutting tool insert suited to heavy interrupted machining of hard materials such as alloy steel and die steel; and the MEGACOAT CBN KBN60M, an insert for high-speed machining of gray cast iron. These new additions featuring increased hardness, wear-resistance, stability and longer tool life will join the Kyocera MEGACOAT CBN (cubic boron nitride) series.

The KBN35M adopts Kyocera's proprietary honeycomb cell fiber structure for CBN inserts. This structure, which is the first of its kind in the industry, drastically improves fracture-resistance - which has been a problem area with heavy interrupted machining of materials with high hardness - doubling the life of Kyocera's conventional models.


Variety 102 inserts 55 inserts
Application Heavy interrupted machining of alloy General high-speed machining of gray cast
  steel and die steel (hard materials) iron
Manufacturing site
Yohkaichi Plant, Shiga Prefecture, Japan
Sales target
500 million yen in first year


In the market for the machining of automotive components, there has been a growing demand in recent years for improved quality in terms of machining precision. Also, because there is a greater need for longer life in high-performance automotive components, hard materials such as alloy steel and die steel are more frequently employed. Such hard materials are processed using CBN inserts for heavy interrupted machining. However, conventional CBN inserts can develop cracks in the blade edge, making it difficult to increase productivity. With increased usage of inserts and rising costs of components materials, demand has grown for inserts with stronger wear-resistance, longer life and higher stability.

Corresponding to the needs of customers, Kyocera introduces an industry-first proprietary cell fiber structure for CBN inserts. Moreover, Kyocera applies its proprietary PVD coating,* MEGACOAT, to provide stronger wear-resistance and double the life of conventional products in heavy interrupted and high-speed machining.
*Physical vapor deposition (PVD) coating: A method of coating the substrate materials by producing a chemical response using electricity or thermal energy.

Gray cast iron is used to manufacture many products such as brake disks in automobiles. In recent years, the need has grown for high-speed machining to enhance productivity. Although CBN inserts with stronger wear-resistance are the most suitable for high-speed machining, there has been a problem with chipping-resistance. With a mix of CBN particles and the introduction of ceramic binders, the KBN60M improves chipping-resistance while maintaining wear-resistance. Kyocera has developed CBN inserts with excellent stability in high-speed machining and a longer life to contribute to improved productivity.

The MEGACOAT CBN series is comprised of inserts with Kyocera's proprietary PVD coating method, MEGACOAT. These feature superior heat- and oxidation-resistance in heavy interrupted and high-speed machining, and provide limited crater wear and stable machining as well.

MEGACOAT CBN KBN35M cell fiber structure enhances stability
Kyocera has developed the KBN35M with higher stability by adopting a honeycomb structure in the cell fibers to provide stronger crack-resistance than conventional models. The new structure limits the advancement of cracking by 50 percent or more.

Blending of CBN particles
Kyocera has developed new CBN materials by blending super-fine 1µm particles featuring increased hardness and durability with rough 6µm particles - which are effective in limiting the advancement of cracking. The materials also improve the wear- and crack-resistance of inserts.

Ceramic binders
Ceramic binders are employed in the KBN60M, which enhance wear- and chipping-resistance over conventional metal compound binders such as aluminum, cobalt or tungsten.

Cell Fiber Structure
Cell fiber structure uses a compound of multiple crystal materials and features a honeycomb structure with vertically arranged fibers using wear-resistant CBN in the core, and crack-resistant CBN in the shell.

CBN structure provides two main features:
1. Stronger wear-resistance in hard material machining.
2. Stronger crack-resistance, limiting the advancement of cracking.
Image: CBN structure provides two main features