Tdk Corporation

Nobuhiro Jingu

Eiji Kato

Chikara Ishizaka

Taeko Tsubokura

Tamotsu Ishiyama

An R-T-B based alloy strip including columnar crystals of an RTB phase, wherein in a cross-section along the thickness direction, columnar crystals extend out in a radial fashion from the crystal nuclei, the R-T-B based alloy strip satisfying the following inequality (1), where Dand Dare, respectively, the average value for the lengths of the columnar crystals on one side and the average value for the lengths on the other side that is opposite the one side, in the direction perpendicular to the thickness direction of the cross-section.0.9/1.1&#x2266;&#x2266;1.1/0.9&#x2003;&#x2003;(1)

R-T-B based alloy strip, and R-T-B based sintered magnet and method for producing same

An R-T-B sintered magnet including a composition containing a rare earth element, a transition element and boron, containing essentially no dysprosium as a rare earth element, and having crystal grains with a composition containing a rare earth element, a transition element and boron, and grain boundary regions formed between the crystal grains, wherein the triple point regions which are grain boundary regions surrounded by 3 or more crystal grains have a composition containing a rare earth element, a transition element and boron and have a higher mass ratio of the rare earth element than the crystal grains, the average value of the area of the triple point regions in a cross-section being no greater than 2 &#x3bc;mand the standard deviation of the area distribution being no greater than 3.

R-T-B based sintered magnet and production method for same, and rotary machine

An R-T-B based alloy strip containing dendritic crystals including a RTB phase, wherein on at least one surface, the average value for the widths of the dendritic crystals is no greater than 60 &#x3bc;m, and the number of crystal nuclei in the dendritic crystals is at least 500 per 1 mm square area.

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Tokyo, Japan

Nobuhiro Jingu