Study of Preparation and Properties of P2O5-Al2O3-SiO2 System Glass-ceramic Diffusion Source of Phosphorus

　　Study of Preparation and Properties of P2O5-Al2O3-SiO2 System Glass-ceramic Diffusion Source of Phosphorus
　　In this thesis, the research object is P2O5-Al2O3-SiO2 system glass-ceramics. According to requires of the product、references and apparatus we had, s set of compositions are designed. Without the change of the basic ingredient, the influence of the content of Al2O3 on the fusion property and the influence of the content of nucleus agent、La2O3 and heat treatment on Ball Neodymium Magnets crystallization、structure、performance of the glass-ceramics was studied. The heat treatment and the composition of the glass were optimized.In the experiment, the structure and appearance of the glass-ceramics were studied by means of DTA、XRD、SEM and so on.
　　The performances are studied by means of heat expansion testing and the weight lost experiment of the glass-ceramics in the high temperature furnace.The result indicates that there is a value of the content of Al2O3 between 24% and 26%, the glass is hard to melt completely in the 1560℃when the content of Al2O3 is beyond this value. And there is a value of the content of Al2O3 between 22% and 24%, the glass is hard to crystallize in the 1560℃when the content of Al2O3 is little than this value. So, the optimal content of Al2O3 should be between 22% and 24%.Without the change of other ingredient, the trend of crystallization of the glass and the release of P2O5 of the glass-ceramics increase with the increase of the content of La2O3, and the heat expansion of the glass-ceramics decrease. But the velocity of this trend will be slow when the content of La2O3 is to some extent. And if the content of La2O3 is too high, it will be affect the fusion of the glass.Without the change of other ingredient, the trend of crystallization of the glass and the release of P2O5 of the glass-ceramics http://www.chinamagnets.biz increase with the increase of the content of nucleus agent ZrO2, and the heat expansion of the glass-ceramics decrease. Because of the fast velocity of the crystallization, the crystallization is hard to control when the content of ZrO2 is beyond 8%. The optimal content of ZrO2 should be between 5% and 8%.The optimal heat treatment that was obtained after using orthogonal method is nucleation in 780℃for 3h、crystallization in 980℃for 4h. The order of affection is crystallization temperature、crystallization time、nucleation temperature、nucleation time. But the heat expansion of the glass-ceramics is affected mainly by crystallization temperature and crystallization time. The influence on heat expansion by the nucleation temperature and nucleation time is limited in the certain range of temperature.