Strong Magnetic Field Forces The Material Microstructure And Properties Of The Impact

With the development of super conducting materials, new-style equipments that can generate D.C. static high magnetic fields have been gradually and successfully manufactured and have been applied in various fields of science. As a result many new academic intercross fields of science, which have very good potential for future development, have come into being. The new field of High Magnetic Field-related Materials Science and Engineering has also formed under this background. As an extreme condition, high magnetic field can make materials put up specials properties. In this regard high magnetic field will affect metal fluid, crystal orientation, the segregation of impurities and solid-state transformation. Recently, investigations were focused on property optimize of materials and the preparation of new materials. So far, many interesting phenomena have been found by using new experimental methods related to high magnetic fields.Firstly, the distribution of the high magnetic field was analyzed which help to use the apparatus effectively and scientifically. Secondly, high magnetic field effects were researched from the point of view of mechanics. Lastly, effects of annealing under high magnetic field on the structure of spheroidal graphite cast iron, gray cast iron and 45# steel were investigated. The solidification of Al-12%Si under high magnetic field was also carried out.The mathematical calculation model of solenoid coil magnetic filed was established by using of single integral method. During the calculation, singular integrals were transformed into general integrals. And in numerical calculation, Romberg quadrature method was used. In the end, the author used VB langrage to design a program to show the distribution of the magnetic field. In the bore of the high magnetic field apparatus, there has an evident difference for the magnetic flux density and it's gradient in different positions. In this regard attentions should be paid in our experiment.Forces working on materials have a close relationship with high magnetic field effects. The levitation position of the ferromagnetism material was calculated according to the magnetization force. The magnetization force of specimens in different positions was also calculated. Crystal alignment and assemblage phenomena in high magnetic field were caused by the reciprocity between magnetic poles. In order to get purified and well-structured materials, Lorentz force was used to segregate impurities and control fluid of molten metal.In the experiment of high magnetic field annealing of spheroidal graphite cast iron, it is found that the dissolving of cementite and diffusion of carbon is increased greatly by imposing high magnetic field. While in the area of crystal boundary, cementite was found to align along the magnetic field direction. For the high magnetic field annealing of gray cast iron, many free carbons were found in pearlite. In 45# steel, pearlite was found to align along the magnetic field after annealing under high magnetic field. In addition, this phenomenon is much obvious in the (8T) position where the gradient is much bigger. During the solidification of Al-12%Si under high magnetic field, no aligned structures were found because corresponding conditions were not satisfied.