不同重力环境下硼铅玻璃的二次分相现象研究

Secondary Phase-Separation of Lead Borate Glass under Different Gravity Conditions

以不同落塔实验所得的硼铅玻璃试样为研究对象,通过微观形貌观察和相分析等手段,研究了硼铅玻璃的二次分相现象。结果发现,所有试样在一次分相形成富硼相和富铅相后,富硼相和富铅相都继续发生了分相,即二次分相现象。不同试样发生二次分相后的微观形貌有很大不同,这主要是由于所发生的二次分相没有遵循现有相图中的不混溶区,而是按照另外一种不混溶区进行的。在PbO-B_2O_3系统中除了已知的不混溶区以外,至少还存在有另外两个不混溶区,这两个不混溶区目前还不能准确定位,本文对这两个不混溶区在相图中的位置进行了大概的估计,而且发现不同重力条件下这些不混溶区在相同中的位置也有很大不同。

The lead borate glass was melted and solidified under different gravity conditions, and microstructure of the samples was observed through SEM. The secondary phase-separation of the glasses were explored and the possible immisibility region existed in the lead borate system was suggested. Results show that the lead borate glass first phase separated into two glassy phases： lead-rich phase and borate-rich phase, which were both believed to continue the phase-separation （secondary phaSe-separation）. The microstructure of the sample is very different, which is attributed to the pattern of secondary phase-separation. In addition to the known immiscibility region in the PbO-B203 system, there are at least two potential immiscibility regions existing, although the exact position can not be determined. It was also found that the position of the immiscibility regions is related to the gravity condition under which the secondary phase-separation happened.