| 摘要 |
PURPOSE:To improve corrosionproofness by dipping an R-Fe-B magnet obtained by sintering a green compact of R-Fe-B alloy powder which indispensably contains rare earth elements including Y, iron and boron in an alkaline aqueous solution, and heat treating it in vacuum or in an inert gas atmosphere. CONSTITUTION:Alkaline aqueous solution which contains 10-30wt.% of one of sodium hydroxide, potassium hydroxide or total amount of sodium hydroxide and potassium hydroxide is prepared, and held at 50-100 deg.C. An R-Fe-B magnet is dipped in the solution for 5-60min, and it is then heat treated by holding it at 300-900 deg.C in vacuum or in an inert gas atmosphere. The component composition of the magnet to be surface treated indispensably contains R, B and Fe, wherein R is Nd, Pr or their mixture, and additionally rare earth element such as Tb, Dy are contained 8-30 atomic% in the total amount while B being 2-28 atomic%. |
