大规格抛光砖抛后变形问题的初步探讨

PROBING PRELIMINARY INTO DEFORMATION OF POLISHED TILES AFTER POLISHING

针对目前全国较多抛光砖生产企业中存在的大规格抛光砖抛后变形的问题 ,本文对抛光砖的坯料及瓷坯分别做了化学成分分析和吸水率测试 ,并利用扫描电镜对瓷坯进行了显微分析。结果表明 ,一方面坯料中Na2 O和SiO2 含量偏高 ,CaO、MgO、Al2 O3含量偏低 ,导致瓷坯中存在较多的钠长石玻璃相 ;另一方面 ,大规格抛光砖较厚 (约 1 0mm) ,抛光砖上下层存在明显的吸水率梯度 ,瓷坯在抛光及放置的过程中吸水后产生不可逆的吸湿膨胀 ,不同部分因膨胀程度不同产生的应力不同 ,从而使坯体抛后变形。

In accordance with deformation of polished tiles after polishing in many plants,chemical composition of its green body was analyzed,absorption of the polished tiles was tested and its microstructure was also observed by the means of SEM in this article.The experimental results show that the content of Na 2O and SiO 2 was a little too high,and its content of CaO、MgO and Al 2O 3 was a little too low.This led to there be too many sodium-feldspar glass phases in it.Meanwhile,the polished tiles with large size were too thick (about 10mm thick).There was an obvious absorption difference between the upper layer and th lower one.During its polishing and storing,the tiles expanded irreversibly by absorbing large amount of water.At different site of the tile there was different expanding degree,therefore existing different stress force.So the tiles deformed.