添加剂对高岭土填料可溶性石膏型芯性能的影响  

Effects of Additives on Properties of Soluble Gypsum Core Filled with Kaolin

作　　者：刘新艾[1] 王猛 黄卫东[1] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072

出　　处：《铸造》2010年第4期395-399,共5页Foundry

摘　　要：研究高岭土填料加入量对石膏混合料性能的影响,并确定高岭土与石膏适合的配比;在此配比的石膏混合料中分别添加MgSO4和NaCl来提高石膏型芯焙烧后抗弯强度及溃散性,并将它们的作用效果进行对比;利用Al(NO3)3的高温分解发气性来改善石膏型芯焙烧线变量。通过SEM观察不同配比试样焙烧后的断口表面形貌,分析添加剂对型芯组织形貌和宏观性能的影响。试验结果表明:高岭土的加入会减小石膏混合料的强度和线变量,其含量为50%时可取得石膏混合料强度和线变量的平衡;MgSO4、NaCl可提高型芯焙烧后抗弯强度和溃散性能,但MgSO4对型芯的抗弯强度及溃散性改善更佳,而使用NaCl作为添加剂时对型芯的焙烧线变量控制较好;加入9%的A(lNO3)3可明显降低型芯焙烧线变量的绝对值。The effect of kaolin filler＇s addition on the properties of gypsum mixture was investigated, and the appropriate ratio of gypsum to kaolin was determined. MgSO4 and NaCl was added in the gypsum mixture respectively to improve the flexural strength and collapsibility of the core after roasting, and their effects on the property of gypsum core were compared. The effect of A（lNO3）3＇s decomposition behavior on the dimension variation of gypsum core during roasting was also investigated. The fracture surface morphology of the samples after roasting with different composition was observed by SEM, and the effects of additives on the microstructure and macroscopic property of core were analyzed accordingly. Experimental results show that, the strength and dimension variation of gypsum mixture is reduced by the adding of kaolin filler. When the content of kaolin was 50%, the strength and dimension variation of gypsum mixture have a good balance. The flexural strength and collapsibility of the core after roasting can be improved by adding MgSO4 and NaCl. It is also discovered that the flexural strength and collapsibility of core are better with the additive of MgSO4, and the dimension variation property of core is better with the additive of NaCl. Moreover, the absolute value of dimension variation of the core during roasting can be effectively decreased by the adding of 9% A（lNO3）3.

关 键 词：石膏型芯 添加剂 抗弯强度 溃散性能 线变量 

分 类 号：TG222[金属学及工艺—铸造]