以聚乙二醇和聚甲醛为主体组分制备了一种用于金属粉末动态注射成型的水溶性粘结剂.通过扫描电镜分析、差示扫描量分析、热重分析、动态流变性能测试、热性能测试、脱脂率实验等对所制备的粘结剂体系进行分析表征.结果表明:粘结剂体系各组分之间有很好的相容性,粘结剂与金属粉末的混合性良好;该粘结剂体系对振动力场的响应良好,能够在振动力场下降低挤出压力,压力最大降幅达6.07%;该粘结剂在水中脱脂速度快,脱脂率高,在75℃水中4h内的脱脂率达43.06%;该粘结剂体系具有良好的热分解性能,添加剂的加入使得热分解温度降低,有利于烧结的进行.
A kind of water-soluble binder suitable for the dynamic injection molding of metal powders was prepared, with polyethylene glycol and polyoxymethylene as the main components. The binder was then characterized by means of SEM, DSC, TG, dynamic rheological test, thermal performance analysis, and degreasing rate test. The results indicate that ( 1 ) the components in the binding system are of good compatibility and the binder perfectly mixes with the metal powders; (2) the binder with good response to the vibration force field can reduce the extrusion pressure by 6. 07% at most; (3) the binder is degreased very fast in water with a high degreasing ratio, and the degreasing ratio is up to 43.06% after a 4-h dipping in water at 75℃ ; (4) the binding system is of good thermal decomposition performance; and (5) additives benefit the sintering because they help to reduce the decom- position temperature.