摘要:
This invention provides permanent magnets that are excellent not only in magnetic properties but also corrosion resistance by using two magnetically useful phases, i.e., RE.sub.2 TM.sub.14 B phase having a high residual magnetic flux density and a low melting point RE-TM' phase or RE-TM'-B phase which enhances the sinterability and possesses a cleaning action against grain boundaries of the RE.sub.2 TM.sub.14 B main phase. Further the invention provides a method for forming an electrochemically noble composition as a starting material to prepare a two phase magnet.
摘要:
A corrosion-resistant rare earth metal-transition metal-boron permanent magnet having improved corrosion resistance and excellent magnetic properties, including RE: 10-25 at % (where RE is at least one of Y, Sc and lanthanides), B: 2-20 at % and the remainder being substantially Fe, Co and Ni. In this case, the magnet has an average crystal grain size of 0.1-50 .mu.m and includes a crystal grain boundary phase of RE(Ni.sub.1-x-y Co.sub.x Fe.sub.y) compound having a thickness of not more than 10 .mu.m.