TDK Corp developed a high-performance magnet that uses only half the amount of neodymium (Nd), a rare-earth metal, and will exhibit it at Ceatec Japan 2014, which will take place from Oct 7 to 11, 2014, in Chiba Prefecture, Japan.
The maximum energy product and Curie point (temperature at which magnetic force is lost) are 40MGOe and 300°C, respectively, which are equivalent to those of neodymium sintered magnets (35-55MGOe and 300°C). In addition, the new magnet contains no dysprosium (Dy).
TDK did not disclose the composition of the magnet but said that it is an "extension" of neodymium sintered magnet. The composition of a neodymium sintered magnet is Nd2Fe14B. The company reduced the amount of Nd by half by replacing it with another metal and making improvements to the grain boundary structure.
"We replaced Nd not with Tb or Dy but with an element that is less likely to be depleted or become difficult to obtain," TDK said.
The new magnet can be manufactured by almost the same manufacturing process as that of existing neodymium sintered magnets, it said.
Currently, TDK does not have a plan to mass-produce the magnet probably because of the following reason. Even if the amount of Nd is halved, it will not significantly reduce cost because the price of Nd is currently moderate.
"To reduce the risk in the procurement of resources, we are now researching rare-earth-free magnets with some approaches," the company said. "This time, we have achieved a certain result and enabled to halve the amount of Nd and eliminate the need for Dy. So, we decided to exhibit it."