Shin-Etsu Chemical Co., Ltd. (Head office: Tokyo, President: Chihiro Kanagawa) has developed a new advanced high-performance technology for sintered neodymium iron boron magnets (Nd magnets).
Shin-Etsu has further developed the binary alloy method^*1 that the company originally developed as a manufacturing method for Nd magnets. By adding a new process to its existing Nd magnet manufacturing method, Shin-Etsu has succeeded in greatly increasing the magnet's coercive force,^*2 a characteristic which has a direct bearing on improving the magnet's special qualities, particularly in raising the heat-resistance performance level of these magnets. As a result of the development of this new high-performance technology, Shin-Etsu has realized the world's highest Nd magnet performance characteristics for the applications at elevated temperature. Shin-Etsu has named this new manufacturing method the "new binary alloy method enhanced by grain boundary diffusion." Patents for this technology have already been applied for in various countries around the world, including in Japan.
In application fields for Nd magnets that are expected to see high growth in the future, such as motors for hybrid cars and compressor motors for air conditioners, both high heat-resistance and high-performance characteristics are required, and accordingly, both high coercive force and a high level of flux density of residual magnetization^*3 are simultaneously desired. However, one limitation of the existing manufacturing method is that in order to raise the coercive force of Nd magnets, it was necessary to add a large quantity of dysprosium(Dy) and/or terbium(Tb). These rare-earth elements are available in limited supplies due to natural balance in rare-earth ores and therefore cost relatively high. At the same time, there were problems caused by adding Dy and other such materials because they lowered the flux density of residual magnetization, which controls the total magnetic characteristics of the magnets.
The new binary alloy method enhanced by grain boundary diffusion developed by Shin-Etsu has succeeded in increasing coercive force by more than 30% while maintaining the flux density of residual magnetization by concentrating elements such as Dy in the magnet's grain boundary. As a result, it has become possible to simultaneously achieve both high heat-resistance and high-performance characteristics.
High growth of the rare-earth magnet market is expected, reflecting the expansion of applications into various fields such as automobiles and home appliances. In particular, the demand for high-performance Nd magnets requiring high heat resistance is expected to grow by more than 20% over the next few years, mainly due to such applications as for hybrid cars, home appliances, particularly air-conditioners, and hard disk drives.
To meet these growing demands, Shin-Etsu will begin sample shipments of products manufactured using this new technology by the end of 2005 and prepare a production system aimed at the start of mass production from 2006. As a consequence of this newly developed high-performance technology for Nd magnets and timely plan to implement mass production, Shin-Etsu is confident that the company will increase its sales share in this growing business field.

*1 Binary alloy method: A type of manufacturing method for Nd magnets. It is a sintering method that involves the mixing two kinds of specific composite alloys.
*2 Coercive force: A magnet's force that tries to maintain magnetic flux against external magnetic fields - a magnet's resistance strength against external magnetic fields.
*3 Flux density of residual magnetization: A value indicating the degree of a magnet's magnetic force. The larger this value is, the more a magnet creates magnetic flux.

Tokyo March 24, 2005