Abstract: A metal film 4 is disposed between a permanent magnet 3 and a rotor yoke 1, and the permanent magnet 3 and the rotor yoke 1 are subjected to beam welding. Since the metal film 4 is disposed between the permanent magnet 3 and rotor yoke 1, and the metal film 4 as a laser beam irradiated portion is melted by vacuum beam or laser beam, the metal film 4 has brazing metal function in welding, so that the connection between the permanent magnet 3 and the rotor yoke 1 is strong. Since there is no need of embedding the permanent magnet 3 in the rotor yoke 1 and there is no need to use polymer adhesives, the cost can be reduced.

Abstract: A rare-earth sintered magnet according to the present invention includes: 28.5 mass % to 32.0 mass % of R, which includes Tb and at least one of the other rare-earth elements; 0.91 mass % to 1.15 mass % of B; at most 0.35 mass % of oxygen; and Fe with or without Co and inevitably contained impurities as the balance. The magnet includes 3.2 mass % to 5.2 mass % of Tb, and has a remanence Br of at least 1.29 T, a coercivity HcJ of at least 2.4 MA/m and a maximum energy product (BH)max of at least 320 kJ/m3.

Abstract: A metal film 4 is disposed between a permanent magnet 3 and a rotor yoke 1, and the permanent magnet 3 and the rotor yoke 1 are subjected to beam welding. Since the metal film 4 is disposed between the permanent magnet 3 and rotor yoke 1, and the metal film 4 as a laser beam irradiated portion is melted by vacuum beam or laser beam, the metal film 4 has brazing metal function in welding, so that the connection between the permanent magnet 3 and the rotor yoke 1 is strong. Since there is no need of embedding the permanent magnet 3 in the rotor yoke 1 and there is no need to use polymer adhesives, the cost can be reduced.

Abstract: A composite magnetostrictive material having a magnetostrictive performance required for a practical use and yet a higher strength. A composite magnetostrictive material 1 is comprised of a matrix 2 formed of a magnetostrictive material of an RM-based alloy, wherein R is a rare earth element and M is one of a transition metal and aluminum, and dispersion phases 3 dispersed in the matrix and formed of at least one of an RM-based metal, R and M.

Abstract: A SmFe-based magnetostrictive material having an excellent magnetostrictive performance and an excellent mechanical strength provided by achieving a division of crystal grains. The SmFe-based magnetostrictive material includes boron (B) as an additive component, which contributes to the fine division of crystal grains. The content of boron (B) is set in a range of B.ltoreq.0.01% by weight.