%0 Journal Article
%T An improved sodium silicate binder modified by ultra-fine powder materials
%A WANG Ji-na
%A FAN Zi-tian
%A WANG Hua-fang
%J China Foundry
%D 2007
%I Foundry Journal Agency
%X This paper presents a new method of modifying sodium silicate binder with ultra-fine powders. The sodium silicate binder modified by ultra-fine powder A and the organic B can reduce the addition amount of the binder. The results indicate that the 24 h strength has increased by 39.9% at room temperature and the residual strength has decreased by 30.7% at 800¡æ, compared to the conventional sodium silicate. An available material to improve the moisture resistance was also found by adding about 2% more inorganic C, and it can increase the moist strength by 20%. In the end, the microanalyses are given to explain the modifying machanism, i. e., the ultra-fine powder A can refine the sodium silicate binder to avoid holes in the binder bond, which can increase the 24 h strength at room temperture, and can lead to more cracks in the bond after the molding sand is heated to 800¡æ. This is because of the stress caused by the new eutectic complex of modified sodium silicate binder.
%K sodium silicate binder modification
%K ultra-fine powder materials
%K bonding strength
%K moisture resistance
%K collapsibility
%U http://www.foundryworld.com/uploadfile/2008111840198909.pdf