摘要
To obtain excellent magnetic properties of machinable REPM prepared by directional solidification (DS) technology, Space A, a composition area with theta=0 degrees similar to 5 degrees where easy axis is parallel to solidified direction of alloys, has been established in Zr-Sm-La-Co-Cu-Fe system. In 2/17+1/5+Co, and 2/17+1/5 region near Co phase of Space A, one obtains: V-f = 80.933 - 2.739Zr - 1.828Sm - 0.773Co - 0.147Cu + 0.415Fe + 0.218La Nonequilibrium solidification process of alloys in 2/17+1/5+Co region, is as follows: L-->Co, L-->2/17, L+2/17-->1/5 and L-->1/(5-x)+1/(5+x). The product of partially completed peritectic reaction, and 1/(5-x) and 1/(5+x) phases can all be transformed into a homogeneous 1/5 phase after solution treatment in 1413 K for 5 h. Containing 3 similar to 6% Co phase magnetically hardened by 0.5 similar to 2.5% V, the DS magnets have been achieved with both improved toughness and excellent coercive force of 520 kA/m.
To obtain excellent magnetic properties of machinable REPM prepared by directional solidification (DS) technology, Space A, a composition area with theta=0 degrees similar to 5 degrees where easy axis is parallel to solidified direction of alloys, has been established in Zr-Sm-La-Co-Cu-Fe system. In 2/17+1/5+Co, and 2/17+1/5 region near Co phase of Space A, one obtains: V-f = 80.933 - 2.739Zr - 1.828Sm - 0.773Co - 0.147Cu + 0.415Fe + 0.218La Nonequilibrium solidification process of alloys in 2/17+1/5+Co region, is as follows: L-->Co, L-->2/17, L+2/17-->1/5 and L-->1/(5-x)+1/(5+x). The product of partially completed peritectic reaction, and 1/(5-x) and 1/(5+x) phases can all be transformed into a homogeneous 1/5 phase after solution treatment in 1413 K for 5 h. Containing 3 similar to 6% Co phase magnetically hardened by 0.5 similar to 2.5% V, the DS magnets have been achieved with both improved toughness and excellent coercive force of 520 kA/m.
