磷酸盐无机铸造粘结剂改性及其热固化砂研究

Modification of Phosphate Inorganic Foundry Binder and Its Heat-cured Sand

通过添加有机膦酸和调整加水量对现有的磷酸盐粘结剂进行改性研究,采用具有加热效率高和加热均匀性好的微波作为热源加热,使砂样快速固化。结果表明,通过加入有机膦酸对粘结剂改性,一方面能提高砂样的抗吸湿性,砂样在相对湿度为55%时的抗拉强度最高达1.93MPa;另一方面有机膦酸的加入明显地降低了粘结剂的粘度,在一定程度上改善了型砂流动性。磷酸盐粘结剂的含水量对粘结剂的粘结强度、粘度、抗吸湿性、型砂流动性、硬化速度等性能也有明显影响,并分析了粘结剂的抗吸湿性机理。

The modification of the existing phosphate binders was carried out by adding phosphonic acid and adjusting water addition.Microwave with high heating efficiency and good heating uniformity was adopted as the heat source to solidify rapidly sand.The results show that it can improve the humidity resistance of the test specimen by adding phosphonic acid to the adhesive,and the tensile strength reaches up to 1.93 MPa under relative humidity of 55%.On the other hand,the addition of phosphonic acid can significantly reduce the viscosity of the adhesive,improving the sand fluidity to a certain extent.Water content of the phosphate binder has also significant effects on the bonding strength,viscosity,humidity resistance,sand fluidity,hardening speed and other properties of the adhesive.Meanwhile,the mechanism of humidity resistance was also analyzed.