Magnetomechanical hydraulic-servo apparatus for investigation of magnetomechanical coupling properties of magnetic materials

An apparatus for carrying out magnetomechanical experiments has been constructed, which allows investigations of the physical and mechanical properties of magnetic materials under the application of coupled uniaxial stress and magnetic fields. The apparatus combines a hydraulically driven mechanical loading system with a dipole electromagnet, which is capable of producing mechanical forces up to 2000 kg and magnetic fields up to 2.4 T with a pole gap of 100 mm. And the mechanical force can be applied in any angle with the magnetic field because the mechanical loading device can be rotated in the pole gap. The apparatus allows the automatic measurement of magnetomechanical parameters under on-line computer control of both the magnetic field and the mechanical force. As an example, the simultaneous measurement of magnetostriction and magnetization at various fixed compressive pre stresses applied in the rod axial axis for Tb_0.3Dy_0.7Fe _1.95 samples are presented.