Tasaki Y
Shika Rikogaku Zasshi. 1979 Apr;20(50):63-8.
The cause of the three shrinkages in the thermal expansion curves of gypsum bonded investments, which were characterized in the previous study, was examined mainly by means of TG-DTA method, X-ray diffraction method and SEM observation. The main results were as follows: 1. The first shrinkage between 100 degrees C and 200 degrees C was caused by the dehydration of gypsum. 2. The second shrinkage between 300 degrees C and 400 degrees C was due to the transformation of soluble anhydrite to insoluble anhydrite. 3. The third shrinkage beginning at the temperature range 700 degrees C approximately 800 degrees C is considered to be related to the sintering of insoluble anhydrite.
在先前的研究中已表征出石膏粘结包埋材料热膨胀曲线中的三次收缩，主要通过热重-差示热分析法（TG-DTA法）、X射线衍射法和扫描电子显微镜观察对其原因进行了研究。主要结果如下：1. 100℃至200℃之间的第一次收缩是由石膏脱水引起的。2. 300℃至400℃之间的第二次收缩是由于可溶性硬石膏转变为不溶性硬石膏所致。3. 始于700℃至800℃温度范围的第三次收缩被认为与不溶性硬石膏的烧结有关。
