多次烧成对电瓷机械性能的影响

Effect of Multiple-Firing on Mechanical Properties of Porcelain Insulator

电瓷的无机粘接及对其表面进行少量的无机修复,都需要进行多次烧成,但对多次烧成对其性能的影响却缺少系统的讨论。本文将试条随同批电瓷产品进行多次烧成,通过测量试条的抗折强度及其强度分散性、显微结构特征及物相成分,讨论了多次烧成对电瓷机械性能的影响。结果表明:随着试条烧成次数的增加,抗折强度有小幅度下降,且强度分散性增大,上釉坯体中这种现象更明显。多次烧成后,晶体异常长大现象并不明显,但石英颗粒周围存在着微裂纹增多且出现扩展现象;主晶相莫来石-石英的量有一定程度减少,且析出了少量方石英相,无定形相含量则明显增多。正是这些原因造成了多次烧成电瓷试条抗折强度逐渐降低,强度的分散性有所增大。

Porcelain Insulators with Inorganic Jointing or Inorganic restoration of glaze defects need to be multiple-firing, but systematic study on the effect of multiple-firing on mechanical properties of porcelain insulator is lack. In this paper, barrel samples are multiple-firing together with the same batch porcelain Insulators. Through measuring the bending strength, standard deviation, microstructure features and phase composition of barrel samples, effect of multiple-firing on mechanical properties of porcelain insulator is discussed. The results indicate that along with the increasing multiple-firing number, the bending strength reduces a little and standard deviation expanded which is more apparent among glazed samples. After multiple-firing, the phenomenon that crystal grew up unusually is not obvious, but there are increasing micro-cracks with extension around quartz particles; The main crystallization phases multi- quartz reduce in some degree along with a small amount of cristobalite separate out, while a large increase in the amount of strength of barrel porcelain samples decrease graduall amorphous phase. It is the reason that the bending y while the standard deviation increased.