凹凸棒粘土对消失模涂料触变性的影响

从提高消失模涂料的触变性出发，采用安徽凹凸棒粘土作为消失模含涂料的触变剂。利用差热分析、电镜、X射线衍射、红外吸收光谱等方法测试了凹凸棒粘土的理化性能。并利用NXS-11型旋转粘度计研究了凹凸棒粘土对消失模涂料触变性的影响，提出了消失模涂料的触变性数学模型。结果表明，安徽凹凸棒粘土的理化性能与美国凹凸棒粘土相似，是一种成分较纯的凹凸棒粘土。凹凸棒粘土是一种优良的消失模水基涂料的触变剂，且凹凸棒粘土与膨润土对涂料触变性的影响有显著的差别，膨润土形成的结构破坏很快，恢复则缓慢；凹凸棒粘土的结构破坏与恢复均是一个比较平缓的过程。

Effect of Attapulgite Clayon Rheopexy of Lost Foam Casting Coating

Attapulgite clay in Anhui was used as rheopexy agent to improve coating rheopexy property of lost foam casting (LFC) coating. The physicochemical properties and structure of Anhui attapulgite clay were studied by various kinds of measurements, including differential thermal, scanning electron microscope, X ray diffractional, infrared adsorption spectrum, et al. By using NXS 11 model rotary viscosimeter, the effect of attapulgite clay on LFC coating's rheopexy behaviors was investigated. And a mathematical model on the rheopexy was obtained. The results show that Anhui attapulgite clay with higher purity is similar to those of Georgia, U.S.A in mineral and physicochemical properties. Also, the attapulgite clay is one of better rheopexy agents used in water base LFC coatings. And the influence of attapulgite on rheopexy is quite different from that of sodium bentonite. The rapid structure destruction and slow recovery take place for bontonite containing coating while both structure damage and resumption are changed gradually for attapulgite clay containing coating.