水分对模具石膏性能及微观结构的影响  

Performance and Mechanism of Model Gypsum Influenced by Water

作　　者：葛静冉 彭家惠[1,2] 彭志辉[1] 赵敏[1] 孙慧[1] 

机构地区：[1]重庆大学材料科学与工程学院,重庆400030 [2]重庆建大建材有限公司,重庆400030

出　　处：《材料科学与工程学报》2016年第3期413-416,共4页Journal of Materials Science and Engineering

基　　金：国家自然科学基金资助项目(50872160)

摘　　要：本文通过干湿循环试验模拟卫生陶瓷模具石膏的工作环境,探究不同工作周期下水分对模具石膏耐溶蚀性、吸水性能及力学性能的影响规律。结果表明:随着循环周期延长模具石膏耐溶蚀性能大幅降低,循环周期从40次增至50次,溶蚀率由9.03%增至12.41%,增幅达37%;吸水率在循环周期50次内呈抛物线形式增长,30次时达到峰值26.34%,50次之后吸水率大幅增加。模具石膏的饱水抗折强度在干湿循环过程中显著下降,由最初的2.67MPa减小至1.71MPa,降幅高达36%。微观结构分析表明:水分干湿循环作用使模具石膏硬化体孔隙率增加,孔径分布粗化,大于50nm的大孔数量显著增加;二水石膏硬化体内晶体呈针棒状结构,晶体之间搭接紧密,经水分干湿循环后二水石膏硬化体晶体粗化,搭接程度降低,晶体结构的稳定性变差。The effects of water on the corrosion-resistance,water absorption capacity and mechanical performance of model gypsum under different working cycles were studied by wetting-drying test,a close simulation of work environment of sanitary ceramics model gypsum.The results showed that corrosionresistance of the model gypsum decreased greatly with the increase of cycle period.As the increase of cycle time from 40 th to 50 th,the corrosion ratio increased by 37% from 9.03% to 12.41%.The water absorption improved in the form of a parabola in 50 cycle times and reached the peak of 26.34% at 30 th.After 50 cycle times,the water absorption was increased significantly.The full water flexural strength dropped markedly in the process of wetting-drying cycle,which was decreased by 36%from 2.67 MPa to 1.71 MPa.Microstructure analysis indicated that the effects of water wetting-drying cycle increased the porosity and enlarged the pore diameter of the model gypsum.At the same time,the number of macro-pore increased significantly.The results also showed that needle-like structure of dihydrate gypsum crystals turned to be loose and coarse,indicating the crystal structure stability decline after the wetting-drying cycle.

关 键 词：模具石膏 干湿循环 宏观性能 微观结构 

分 类 号：TQ177.3[化学工程—硅酸盐工业]