【摘要】 针对α-半水石膏粉与石英粉混合制成的硬化体,进行热膨胀率测试,结果表明:石膏混合料中含有70%的石英粉后,硬化体的线膨胀率显著提高;石英颗粒的中位径在27μm到120μm之间时,石膏硬化体的线膨胀率随石英粉的粒度降低而减少;100 g固体混合料用水量在38 ml到48 ml范围内时,硬化体的线膨胀率随着用水量增加而降低。石英粉料粒度及用水量对硬化体热膨胀率的影响规律,对解决石膏铸型材料使用过程中的热收缩问题有一定的指导意义。更多还原

【Abstract】 Gypsum-bonded investment material was prepared by mixed 30% of semi-hydrated gypsum powder and 70% of silica powder.The thermal expansion of the investment material was tested and the results showed that the linear expansion of the investment material was affected by the granularity of silica powder and the quantity of water.At the temperature of 700 ℃,the linear expansion of the investment material decreased with finer silica powder in the D50 ranging from 27 μm to 120 μm.When the quantity of water increased from 38 ml to 48 ml per 100 g investment material,the linear expansion of the investment material also decreased.更多还原