Fractography of cast gypsum.
Fractography of cast gypsum.
复制标题
铸造石膏的断口分析。
作者：
T. Mori;M. Yamane
本文对牙科铸造石膏进行了断口分析，以研究其力学性能与微观结构之间的关系。湿试样在拉伸应力下断裂显示沿晶断裂，拉伸强度取决于存在的孔隙率。因此，假设拉伸强度取决于单个石膏晶体之间的接触面积，并且孔隙率的变化近似于接触面积的变化。因此，给定W/P比的试样之间的强度差异与晶间接触面积的差异有关。这些理论上的考虑表明，仅根据强度特性将牙科模具石和牙科石分为高强度和低强度类型将比目前更实用且更少混淆。
A fractographical study of dental cast gypsum was made in order to correlate the mechanical properties with the microstructure. Wet specimens fractured under tensile stress showed intercrystalline fracture and the tensile strength depended on the porosity present. Thus, it was assumed that tensile strength was dependent on the contact area between individual gypsum crystals and changes in porosity approximated to changes in contact area. Strength differences among specimens of a given W/P ratio, therefore, can be related to differences in intercrystalline contact areas. These theoretical considerations suggest that the classification of dental die stone and dental stone into high and low strength types based on strength properties only would be more practical and less confusing than at present.