| 摘要 |
PURPOSE: To provide a R-TM-B sintered magnetic alloy having highly reliable corrosion resistance by providing with the specified number of recessed part having its specified depth which exist in a grain boundary on the surface of the sintered magnetic alloy. CONSTITUTION: This sintered magnetic alloy is composed of, by wt.%, 5-40 R (R is the combination of a kind or more of rare earth elements including Y.), 50-90 TM (TM is a transition metal mainly including Fe, a part of which may be substituted by the other metal or non-metal.) and 0.2-8 B (boron). The recessed part >=102 piece/cm<2> of the depth of >=3μm<=20μm, which exist on a part of the grain boundary and its vicinity in the surface of the alloy, are formed. A chemical for etching is used so as to form the recessed part. An Ni plating layer is formed on the surface of the sintered magnetic alloy. By this method, adhesion strength between R-TM-B sintered alloy and its plating is reinforced. |
