Study On The Self-propagating High Temperature Synthesis Under Simulated Microgravity Environment Produced By Gradient Strong Magnetic Field

The behavior of heat and mass transfer, melting and solidification during the Self-propagating High Temperature Synthesis(SHS) would change a lot under microgravity, which makes some special materials can be synthesized under the environment, and the products are of high purity, high porous and gradient content. The research team of the author proposed the SHS under gradient strong magnetic field simulated microgravity, which overcomes the shortages of short duration or great cost of traditional means of microgravity. The paper studies the heat, mass transfer and some basic problems of SHS under gradient strong magnetic field simulated microgravity. The main contents and conclusions are as follows.Through the mechanics analysis, the basic characterization of microgravity is concluded as: the supporting force between any internal element of a matter decreases or vanishes. The current means of microgravity and its effect simulation can then be classified into 3 kinds: â‘  the real microgravity environment resulted from the relative motion change, â‘¡ the microgravity simulation resulted from the counterbalance of gravity, â‘¢ the " biology effects" simulated microgravity resulted from the active time of organism less than the change of gravity. These basic concepts are helpful for understanding and preventing the mistakes of microgravity and its application.The basic character of a gradient strong magnet is measured and analyzed, in particular considering doing SHS test inside it. It is found the microgravity can be less than 10^-1g if the position of the container of SHS is from 35mm to 45mm at z axis.A strong magnet is designed and fabricated, which is used as the environment initiator for studying the effects of magnetic field on SHS. The magnet consists of a pair of rotatable permanent magnets and two electric solenoids, by which the magnetic field can be easily changed from 0-1T. The magnet has the advantage of low cost and convenience compared with other magnets which have the same performance. The magnets can be applied to other scientific experiments in the magnetic field.