Fabrication, Structure And Property Of Semi-magnetic Alloy

The alloy of 2 J4, a kind of industrial semi-magnetic material, is widely used as the rotor of magnetic retardation electromotor gyroscope navigation devices in aviation and so on because of its excellent magnetic retardation performance. The usual processing route makes its utility cost high for its limitations. This paper puts forward a new processing way, Equal Channel Angular Pressing (ECAP), to make block semi-manetic materials for the problem of low utility rate. The feature of the style is that it can obtain large true strain per pass deformation, which was often used to obtain the ultra-fined grained material because it can realize severe plastic shearing deformation. The paper mainly studied the feasibility useing ECAP to make block semi-magnetic material.ECAP of 2J4 alloy at room temperature with route A was carried out successfully and block shape 2J4 alloy has been obtained in the experiment. The the maximum equivalent true strain ~3, equivalent to the depressing rate of 90% in the experiment. The microstructure of the alloy deformed was investigated by means of optical microscopy (OM) and transmission electron microscopy (TEM). Its magnetic performance was also measured analyzed and compared with the one of cold rolling. The main results are obtained as following: (1) ECAP of 2J4 alloy at room temperature with route A has been carried out successfully and the block 2 J4 Alloy has been made in the experiment. (2) The theory of the 2J4's phase transformation is stress- induced. The tissue transformation of γ→α' is carried out under the severe plastic shearing deformation. (3) The more the deformation extent is, the larger the martensite's transformation will be.The relation between them is positive pertinence. (4) thespecimen of ECAP shows better magnetic retardation performance than the cold rolled one with the similar deformation quantity with the larger number of coercive force(H_c) remanence(B_r) and most magnetic energy(BH)_max The result shows that the deformation styele is feasible.