Particle and pore size distributions of investments.
Particle and pore size distributions of investments.
复制标题
投资的颗粒和孔径分布。
DOI：
10.1111/j.1365-2842.1986.tb00672.x
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发表时间：
1986
影响因子：
2.9
通讯作者：
Mueller,HJ
中科院分区：
文献类型：
--
作者：
Mueller,HJ
分别通过电区粒度分析和压汞扫描孔隙率测定法研究了不同包埋料粉末的粒度分布和集烧包埋料的孔径分布，这些包埋料代表了所有三种可用类型，即：石膏-，磷酸盐-和硅酸盐-粘结。孔体积（V）、孔表面积（S）及其相对于半径r的一阶导数dV/dranddS/dr在压力高达414 MPa时获得，对应于半径为0.0018 μm的球形孔（如果适用Washburn方程）。结果区分了一系列不同尺寸的孔隙。除了由于基质粘合剂的孔隙率，孔隙率也归因于耐火组分。后一种类型的孔隙发生在孔隙半径低于约0.03 μm时，而基质孔隙发生在该孔径以上。磷酸盐材料的基质孔隙率最小，半径约为0.03至0.5 μm，其次是石膏材料，半径约为0.3至0.6 μm，硅酸盐材料的半径约为1至10 μm。包埋料粉末的粒度分布可能会影响两种类型的孔隙率，而特定包埋料类型的凝固化学成分可能会通过生成气态副产物影响基质孔隙率。气固和吸湿固材料之间的孔径和分布无重大差异。本研究强调，目前，仅了解总孔隙体积不足以表征孔隙度分布以及投资渗透率。
The particle‐size distributions of investment powders and the pore‐size distributions of set‐fired investments were investigated by electrozone size analysis, and by mercury intrusion scanning porosimetry, respectively, for a number of different investments, representing all three types available, namely: the gypsum‐, phosphate‐ and silicate‐bonded. The pore volume (V), the pore surface area (S), and their first derivatives with respect to radius,r,dV/dranddS/dr, were obtained with pressures up to 414 MPa corresponding to spherical pores of 0.0018 μm radius if the Washburn equation is to apply. Results distinguished pores with a range of different sizes. Besides the porosity due to the matrix binder, porosity was also attributable to the refractory components. This latter type of porosity occurred with pore radii below about 0.03 μm, whereas matrix porosity occurred above this pore size. Matrix porosity for the phosphate materials was smallest at about 0.03 to 0.5 μm in radius, followed by the gypsum materials at about 0.3 to 0.6 μm, and by the silicate materials at about 1 to 10 μm. The particle‐size distribution of the investment powders may affect both types of porosities, whereas the setting chemistries of the particular investment types may affect matrix porosity, by the generation of gaseous by‐products. No major distinctions in pore size and distributions occurred between air‐set and hygroscopic‐set materials. This study emphasizes that at present, knowledge of the total pore volume only is inadequate for characterizing porosity distribution and hence investment permeability.