翟欣姣 侯击波 毛红奎 赵永生
Effects of Additives on the Performance of Investment Gypsum
Zhai Xinjiao, Hou Jibo, Mao Hongkui, Zhao Yongsheng
(College of Materials Science and Engineering, North University of China)
Abstract: With different additives mixed into investment gypsum casting powder, the effects of different additives on the fluidity, solidified time and baked strength of investment gypsum casting powder were investigated. The results show that the polycarboxylic acid water reducing agent has severely retarded the gypsum casting powder slurry, although enhancing the fluidity of the gypsum casting powder slurry, and the 0.1% content is more suitable for gypsum casting powder. When less silica sol is added to the water and the ratio of water to silica sol is less than 1∶1, the silica sol can promote the fluidity of the gypsum casting powder slurry, appropriately increasing the solidified time, and increasing the strength of the gypsum casting mold. When the ratio of water to silica sol is 4∶1, the fluidity of the gypsum casting powder slurry is satisfied. When the water: silica sol is 1∶1, the strength of the gypsum mold is desirable.
Key Words: Additives, Fluidity, Solidified Time, Baking Strength, Gysum Mold