宝珠覆膜砂固化工艺参数优化研究  

Optimization on Curing Process for Pearl Coated Sand

作　　者：张睿亭 刘慧婷[1] 薛鸿舰 刘越[1] 

机构地区：[1]东北大学材料科学与工程学院,辽宁沈阳110819

出　　处：《铸造技术》2017年第8期1940-1943,1952,共5页Foundry Technology

基　　金：辽宁省科技创新重大专项(201404001);大学生创新训练计划项目(161037)

摘　　要：为改善宝珠覆膜砂型壳的品质,提高铸件表面精度,通过不同固化温度和固化时间制得宝珠覆膜砂试样,测试宝珠覆膜砂抗拉和抗弯强度及发气性含量,分析不同固化工艺参数对宝珠覆膜砂性能的影响规律。研究结果表明,固化温度小于230℃时,随着固化温度的升高,宝珠覆膜砂抗拉和抗弯强度值逐渐升高,固化温度>230℃时,随着固化温度的升高,宝珠覆膜砂抗拉和抗弯强度值逐渐降低;固化时间小于120 s时,随着固化时间的延长,宝珠覆膜砂抗拉和抗弯强度值逐渐升高,固化时间大于120 s时,随着固化时间的延长,宝珠覆膜砂抗拉和抗弯强度值逐渐降低。当固化温度230℃,固化时间120 s时,宝珠覆膜砂抗拉强度最大值为1.644 MPa,抗弯强度最大值为4.781 MPa。在此工艺条件下,宝珠覆膜砂之间的断裂以内聚断裂为主,内聚断裂的强度要高于附着断裂。In order to improve the quality of coated sand shells and the surface accuracy of castings, the effects of curing temperature and curing time on the properties of pearl coated sand were analyzed by testing the strength and gas evolution of the pearl coated sand samples in different process conditions. The results show that, when the curing temperature is lower than 230 ℃, the tensile and the flexural strength increase with the increase of curing temperature. When the curing temperature is higher than 230 ℃, the tensile and the flexural strength gradually reduce with the increase of curing temperature. When the curing time is less than 120 s, the tensile and the flexural strength increase with the curing time prolonging. When the curing time is longer than 120 s, the tensile and the flexural strength of the pearl coated sand gradually reduce with the curing time prolonging. When the curing temperature is 230 ℃ and the curing time is 120 s, the maximum of tensile strength is 1.644 MPa and the maximum of flexural strength is 4.781 MPa. Under the condition of this process, the fracture between the pearl coated sand is dominated by the cohesive fracture and the strength of the cohesive fracture is higher than that of the fracture. Therefore, the optimum curing process is the curing temperature of 230 ℃ and the curing time of 120 s.

关 键 词：宝珠覆膜砂 固化温度 固化时间 强度 发气性 

分 类 号：TG221.1[金属学及工艺—铸造]