微孔硅酸钙柔性隔热材料的显微结构和导热性能  

Microstructure and Thermal Conductivity of Flexible and Micro-Porous Calcium Silicate Insulation Material

作　　者：李懋强[1] 石兴[1] 

机构地区：[1]中国建筑材料科学研究总院,北京100024

出　　处：《稀有金属材料与工程》2007年第A01期575-578,共4页Rare Metal Materials and Engineering

摘　　要：微孔硅酸钙柔性隔热材料由以硬硅钙石针状微小晶体构成的微孔硅酸钙球形颗粒和硅酸铝纤维复合而成,其中大部分硅酸铝纤维首先形成柔软的纸型材料,微孔硅酸钙颗粒和其余硅酸铝纤维沉积其上,填充在硅酸铝纤维之间的大孔隙中。由于微孔硅酸钙颗粒被硅酸铝纤维分割,互相之间不能通过氢键直接相连,从而无法形成普通微孔硅酸钙材料所具有的刚性结构,只能借助硅酸铝纤维构成柔性结构。具有大量0.1～1μm直径孔隙的微孔硅酸钙颗粒极大程度地限制了材料内空气的对流传热,同时,实验发现减少大孔隙和适当增加材料的致密度可以降低辐射传热,从而进一步降低材料的导热系数。这种复合材料的表观密度为0.25-0.32g/cm3,热面温度1000℃下的表观导热系数可低至0.08W/(m·K)。Flexible micro-porone calium silicate insulation material is composed of porous spherical agglomerates consisting of many tiny needlelike xonotlite crystals and aluminum silicate fiber, most part of which has been formed flexible ceramic fiber paper before formation of the insulation material. The calcium silicate spherical agglomerates and the rest part of the aluminum silicate fiber deposit on the preformed ceramic fiber paper. The calcium silicate spherical agglomerates filled into the voids constructed by calcium silicate fiber in the ceramic fiber paper are isolated by the fiber, blocking formation of hydrogen bonds among the agglomerates in the different voids, which arise in the ordinary micro-porous calcium silicate insulation material causing its rigidity. Flexibility of the composite paper consisting of calcium silicate agglomerates and aluminum silicate fiber results from the above-mentioned structure. Heat transfer due to solid conduction and gas convention is reduced very much because of the existence of large amount of pores with their diameters in the range from 0.01 to 1 μm in the calcium silicate agglomerates. The agglomerates filled in the voids of aluminum silicate fiber paper block thermal radiation. Therefore, the heat transfer is reduced further. The prepared insulation material possesses low density as 0.25-0.32 g/cm^3, and low thermal conductivity as 0.08 W/（m·K） at the temperature of the hot face being of 1000 ℃.

关 键 词：隔热材料 微孔硅酸钙 硅酸铝纤维 

分 类 号：TB383.4[一般工业技术—材料科学与工程]