Abstract: To provide a method for producing a magnetostrictive material of excellent magnetostrictive characteristics. The method for producing a magnetostrictive material, wherein a mixture composed of Starting Materials A, B and C is sintered, where A is represented by Formula 1 (TbxDy1-x)Ty (T is at least one metallic element selected from the group consisting of Fe, Ni and Co, 0.35<x?0.50 and 1.70?y?2.00), B is represented by Formula 2 DytT1-t (0.37?t?1.00), and C contains T, to produce a magnetostrictive material represented by Formula 3 (TbvDy1-v)Tw (0.27?v<0.50, and 1.70?w?2.00), wherein oxygen content is set at 500 to 3,000 ppm for Starting Material A and at 2,000 to 7,000 ppm for Starting Material B.

Abstract: It is an object of the present invention to provide a sensor, a magnetostrictive element or the like having temperature stabilities. The sensor of the present invention for sensing a pedal pressure in an electric hybrid bicycle comprises a magnetostrictive element and a coil arranged on the outer circumferential side of the element, wherein the element is composed of a sintered body having a composition represented by TbxDy(1-x)Ty, wherein x is in the range: 0.50<x?1.00, T represents one or more transition metal elements, and y is in the range: 1<y<4. The sensor of the above structure has temperature stabilities. The electric hybrid bicycle can stably generate an auxiliary force, when incorporated with the torque sensor.

Abstract: To provide a method for producing a magnetostrictive material of excellent magnetostrictive characteristics. The method for producing a magnetostrictive material, wherein a mixture composed of Starting Materials A, B and C is sintered, where A is represented by Formula 1 (TbxDy1-x)Ty(T is at least one metallic element selected from the group consisting of Fe, Ni and Co, 0.35<x?0.50 and 1.70?y?2.00), B is represented by Formula 2 DytT1-t (0.37?t?1.00), and C contains T, to produce a magnetostrictive material represented by Formula 3 (TbvDy1-v)Tw (0.27?v<0.50, and 1.70?w?2.00), wherein oxygen content is set at 500 to 3,000 ppm for Starting Material A and at 2,000 to 7,000 ppm for Starting Material B.

Abstract: A setter 20 to be arranged in a sintering container 10 is provided with holes 21 to keep a compact 100 upright. The compact 100 is not in contact with the setter 20 at a temperature level at which the sintering reaction proceeds between them because of contraction of the compact 100 during sintering.

Abstract: In the step of sintering a compact that is finally to be a magnetostrictive element, when the temperature in a furnace is elevated, the atmosphere in the furnace is evacuated by a vacuum pump to keep the pressure in the furnace at negative pressure in a temperature range that allows thermal decomposition of hydride present in the compact to release hydrogen gas to accelerate release of hydrogen from the compact.

Abstract: A method for manufacturing a sintered compact includes the steps of preparing an alloy powder having a composition represented by Expression 1: RTW (where, R is at least one kind of rare earth metal, T is at least one kind of transition metal, and w defines a relation of 1<w<4), sintering the alloy powder in a vacuum atmosphere or an atmosphere containing gas with a molecular weight of 30 or less, and processing the alloy powder by a hot isostatic pressing. The sintered compact has a high density, and reduces deteriorations in its sintered compact properties such as magnetostrictive properties in an air atmosphere at high-temperatures.