| 摘要 |
PURPOSE:To manufacture a high-density RCo5-type sintered alloy magnet excellent in magnetic properties, by allowing a green compact prepared by compacting an RCo5-type alloy powder (R means rare-earth element of Y) to occlude hydrogen, dehydrogenating the above in an Ar atmosphere and then carrying out sintering. CONSTITUTION:A powdered raw material composed principally of RCo5-type alloy powder (where R means one or more kinds among rare-earth elements and Y) is compacted. This green compact is held in a hydrogen air flow at the prescribed temp. in a range between ordinary temp. and 200 deg.C for a prescribed period to undergo occlusion of hydrogen. The resulting hydride is subjected to complete dehydrogenation at the prescribed temp. of <=900 deg.C by converting a hydrogen atmosphere into an Ar atmosphere to remove residual hydrogen. By the above procedure, the growth of crystalline grains at the time of sintering is prevented and the configuration of crystal atoms in the above powdered raw material is regularized to improve sintering characteristics. Subsequently, this green compact is sintered in an Ar atmosphere at the prescribed temp. in the range between 1,100 deg.C and 1,200 deg.C. In this way, the RCo5-type sintered alloy magnet excellent in all the magnetic properties of coercive force, residual magnetic flux density, and maximum energy product can be obtained. |
