铝磷酸盐热硬砂粘结机理探讨  

Discuss of Bond Mechanism of Al-phosphate Hot Cured Sand

作　　者：夏露[1] 张友寿[1] 黄晋[1] 董仕杰[1] 李四年[1] 

机构地区：[1]湖北工业大学机械工程学院,湖北武汉430068

出　　处：《铸造技术》2011年第1期27-30,共4页Foundry Technology

基　　金：湖北省科技厅自然基金项目(2009CDB297)

摘　　要：结合铝磷酸盐热硬砂干强度测试,借助于扫描电子显微镜和电子探针,探讨了铝磷酸盐热硬砂的粘结机理,并分析了改性剂对热硬砂粘结机理的影响。结果表明:铝磷酸盐热硬砂的断裂以附着断裂为主,且属于脆性断裂,砂粒之间粘结点较少,热硬砂干强度较低。同时加入含镁改性剂和含硼改性剂可使铝磷酸盐热硬砂粘结膜的断裂方式由附着断裂和脆性断裂转变为内聚断裂和塑性断裂,减少并细化了粘结桥的裂纹,提高了热硬砂的干强度。加入含镁改性剂后,在粘结剂密度相同的情况下,提高了粘结剂的粘度,增加了砂粒之间的接触点,提高了热硬砂的干强度。Based on the dry strength testing of Al-phosphate hot cured sand samples,the bond mechanism was discussed,and the effect of modifier on bond mechanism was analyzed by SEM and EMPA.It is revealed that fracture mode of Al-phosphate hot cured sand sample is basically adhesive fracture and brittle fracture with low dry strength and small among of binding points between sand particles.Fracture mode of Al-phosphate hot cured sand is changed from adhesive fracture and brittle fracture to cohesive fracture and plastic fracture and the binding bridge are refined and amount of cracks in binding bridge are reduced after adding magnesium containing modifier and boron containing modifier simultaneously.Viscosity of binder is improved at the same density after adding magnesium-containing modifier,and binding points between sand particles are increased,so that the dry strength is improved too.

关 键 词：铝磷酸盐热硬砂 粘结机理 干强度 附着断裂 内聚断裂 

分 类 号：TG221[金属学及工艺—铸造]