Effect of temperature increase during plastic deformation on ferromagnetic property of composite magnetic material

In press-forming of ferromagnetic/nonmagnetic composite material, an effective process for determining ferromagnetic property was developed using deformation-induced martensitic transformation. In a fixed-temperature compression test, the incidence of deformation-induced martensite was investigated, and measured values were expressed as a sigmoid function. The sigmoid function was introduced into the FEM analysis. During the ironing process, the distribution of effective strain, the distribution of working temperature and the incidence of deformation-induced martensite were calculated, and the ferromagnetic level was predicted to correspond to the incidence of deformation-induced martensite. Based on this experimental assessment, drawing was quite effective for obtaining strong ferromagnetic property compared to ironing. A magnetic flux density B4K(induction at H of 4000A/m) of 0.5T was achieved by drawing under cooling die.