Preparetion And Mechanism Study Of Ti₃SiC₂ By Laser-induced Shs Of Synthesizing Technology

Ti₃SiC₂ is a kind of ceramic materials, which has been widespread concern by material scientists. It has been the important aim of the research in the field of new materials, because of its excellent performance. To date, there are many methods have been used for synthesizing Ti₃SiC₂ in domestic and foreign, but most of them have a lot of problems, for example,complex and longer process, much money spend on the equipment, and so on. Those things limit it to producing and application.In this paper, a new synthetic technology, which has simple process, low cost, easy using,has been using, it was named Laser-induced SHS technology and we used this kind of method to study the kinetics and reaction thermodynamic of this new material. It cans provide theoretical guidance for controlling Laser-induced SHS to synthesizing Ti₃SiC₂, reducing blindness of testing, saving funds and obtaining the material with the ideal structure.The results showed that:?1? In the Laser-induced SHS technology method to synthesizing Ti₃SiC₂, the products were consisted of Ti₃SiC₂ ?TiC ? Ti5Si3; Under a certain degree, the content synthesis of Ti₃SiC₂ could improve with adding the right amount of Si; With adding an appropriate amount of Al, the content synthesis of Ti₃SiC₂ was promoted, but when it exceeds a certain value,there was no significant effect. There was a more obvious reaction phenomenon, when the relative density of the sample is 60%; the relative density of the sample was low or high,cracking happened in the sample or the reaction cannot move.?2? Through thermodynamic analysis, the results showed that: the reaction adiabatic temperature exceeds the required conditions of Self-propagating, the reaction of SHS can happened. The results showed that stability sequence were Ti₃SiC₂?Ti5Si3?SiC?TiC in the high temperature.?3? Through the study of kinetics, we can got it that the reaction mechanism ofLaser-induced SHS technology methods to synthesizing Ti₃SiC₂, which was solutionreaction-precipitation. First the liquid tissue of Ti5Si3 were formed with the temperature increased, at the same time, TiC had been generated and a mount of the liquid tissue of Ti5Si3 wrapped TiC. With the reaction proceeds, Ti₃SiC₂ was generated in their contact surfaces.