【摘要】 本文着重研究环境湿度、原砂水分和含泥量等对呋喃树脂、酚醛树脂、酚醛尿烷树脂和多元醇—聚氨酯等各种不同树脂砂在固化、存放中强度的影响。从性能测试和扫描电镜分析其变化规律,得出水分子的渗透和泥分杂质的存在,在砂粒表面和粘结桥之间形成弱界面层,由于弱界面层的解吸作用和阻碍粘结剂对砂粒表面的润湿,大大降低界面的附着力,导致粘结桥附着破裂。更多还原

【Abstract】 The strength variation of resin sand during curing and storing period is influenced by the ambient humidity, Sand moisture and clay content, Different resins are investigated in this study such as Furan/acid, Phenolic/acid, Phenolic/isocyanato and Polyol Urethane. From the results of performance tests and S. E. M analysis, there is a weak boundary layer formed between the sand grain surface and the binding bridge owing to the penetration of H₂O molecules and the presence of clay on the grain surface. The weak boundary layer leads to a poor wettability of resin binder to the grain surface, the adhesive strength is remarkably decreased and consequently causes the adhesive breakdown of the resin sand.更多还原