摘要
Hygroscopicity-resistance of an α-starch based composite binder for dry sand molds (cores) has been studiedexperimentally and theoretically. Focus is placed on the relationship between the hardening structure andhumidity-resistance of the composite binder. The results show that the α-starch composite binder has goodhumidity-resistance due to its special complex structure. SEM observations illustrate that the composite binder consists ofreticular matrix and a ball- or lump-shaped reinforcement phase, and the specific property of the binding membrane withheterogeneous structure is affected by humidity to a small extent. Based on the analyses on the interplays of differentingredients in the binder at hardening, the structure model and hygroscopicity-resistant mechanisms of the hardeningcomposite binder were further proposed. Moreover, the reasons for good humidity-resistance of the composite binderbonded sand are well explained by the humidity-resistant mechanisms.
Hygroscopicity-resistance of an α-starch based composite binder for dry sand molds (cores) has been studiedexperimentally and theoretically. Focus is placed on the relationship between the hardening structure andhumidity-resistance of the composite binder. The results show that the α-starch composite binder has goodhumidity-resistance due to its special complex structure. SEM observations illustrate that the composite binder consists ofreticular matrix and a ball- or lump-shaped reinforcement phase, and the specific property of the binding membrane withheterogeneous structure is affected by humidity to a small extent. Based on the analyses on the interplays of differentingredients in the binder at hardening, the structure model and hygroscopicity-resistant mechanisms of the hardeningcomposite binder were further proposed. Moreover, the reasons for good humidity-resistance of the composite binderbonded sand are well explained by the humidity-resistant mechanisms.
