Abstract: A rare earth permanent magnet is prepared by immersing a portion of a sintered magnet body of R1—Fe—B composition (wherein R1 is a rare earth element) in an electrodepositing bath of a powder dispersed in a solvent, the powder comprising an oxide, fluoride, oxyfluoride, hydride or rare earth alloy of a rare earth element, effecting electrodeposition for letting the powder deposit on a region of the surface of the magnet body, and heat treating the magnet body with the powder deposited thereon at a temperature below the sintering temperature in vacuum or in an inert gas.

Abstract: A rare earth permanent magnet is prepared by immersing a portion of a sintered magnet body of R1—Fe—B composition (wherein R1 is a rare earth element) in an electrodepositing bath of a powder dispersed in a solvent, the powder comprising an oxide, fluoride, oxyfluoride, hydride or rare earth alloy of a rare earth element, effecting electrodeposition for letting the powder deposit on a region of the surface of the magnet body, and heat treating the magnet body with the powder deposited thereon at a temperature below the sintering temperature in vacuum or in an inert gas.

Abstract: A rare earth permanent magnet is prepared by immersing a portion of a sintered magnet body of R1—Fe—B composition (wherein R1 is a rare earth element) in an electrodepositing bath of a powder dispersed in a solvent, the powder comprising an oxide, fluoride, oxyfluoride, hydride or rare earth alloy of a rare earth element, effecting electrodeposition for letting the powder deposit on a region of the surface of the magnet body, and heat treating the magnet body with the powder deposited thereon at a temperature below the sintering temperature in vacuum or in an inert gas.

Abstract: An electrodepositing apparatus is provided comprising an inner tank (1) filled with an electrodepositing solution, an outer tank (3), a feedback means (4), a rectifying member (5) disposed in the inner tank (1), a means (8) for holding an article (p), a counter electrode (6), and a power supply (9). The electrodepositing solution is circulated in such a way that it overflows the inner tank and is fed back from the outer tank to the inner tank by the feedback means, the flow of the solution is rectified by the rectifying member to keep flat the solution surface in the inner tank, a selected portion of the article is immersed in the solution, and the coating agent is electrodeposited on the selected portion of the article.

Abstract: Provided is a hydrogen absorbing alloy powder for use in nickel-metal hydride storage batteries having a high capacity, excellent initial characteristics and a long life. Specifically provided is a process for the production of a hydrogen absorbing alloy powder which includes the steps of treating a hydrogen absorbing alloy powder with an acid solution, and subsequently treating the hydrogen absorbing alloy powder with a solution containing a condensed phosphoric acid having 2 to 20 phosphorus atoms per molecule and/or phytic acid, as well as an electrode formed of the hydrogen absorbing alloy powder produced by the above process.

Abstract: Provided is a hydrogen absorbing alloy powder for use in nickel-metal hydride storage batteries having a high capacity, excellent initial characteristics and a long life. Specifically provided is a process for the production of a hydrogen absorbing alloy powder which includes the steps of treating a hydrogen absorbing alloy powder with an acid solution, and subsequently treating the hydrogen absorbing alloy powder with a solution containing a condensed phosphoric acid having 2 to 20 phosphorus atoms per molecule and/or phytic acid, as well as an electrode formed of the hydrogen absorbing alloy powder produced by the above process.

Abstract: A method of producing a hydrogen absorbing alloy powder, which comprises a step of treating a pulverized hydrogen absorbing alloy with a solution comprising a condensed phosphoric acid having 2 to 20 phosphorus atoms, phytic acid or a mixture thereof; and a negative electrode using a hydrogen absorbing alloy powder produced by the aforesaid method, which can ensure high initial activity and high initial capacity in the nickel-hydrogen secondary battery provided therewith.

Abstract: A method of producing a hydrogen absorbing alloy powder, which comprises a step of treating a pulverized hydrogen absorbing alloy with a solution comprising a conjugated unsaturated compound having at least 5 conjugated .pi. bonds and a molecular weight of at least 100 and, prior to the this step, optionally comprises a step of treating a pulverized hydrogen absorbing alloy with a mineral acid or alkali; and an electrode using a hydrogen absorbing alloy powder produced by the aforesaid method.