Study On Phosphate Inorganic Binder And Its Application

Casting binder as an important branch in the field of other materials， it plays avital role in the development of foundry industry. Based on the advantages anddisadvantages of the existing casting binder， main problems of the necessity of studyon new phosphate inorganic binder and the binder， experiments were conducted tostudy the effect of modifying agent on the adhesive properties， using scanning electronmicroscope on the morphology of self hardening sand phosphate was observed， andthe mechanism analysis. Focusing on the modified phosphate binder in the applicationof self hardening sand and resin coated sand.Through the modification of the binder and found， poly vinyl acetate emulsion，polyvinyl butyral (PVB)， polyvinyl alcohol and other organic matter does not improveadhesive performance; Found through the study of magnesium chloride modifiedphosphate binder， magnesium chloride can improve the stability of the high school anddegree of phosphate binder， the stability of low neutralization degree of phosphatebinder effect is not obvious; Magnesium chloride modified phosphate binder additionamount was4%，20%for the amount of curing agent， can obtain the tensile strengthof1.24MPa self-hardening sand， than no modification of phosphate self-hardeningsand， tensile strength increased by more than29%.By scanning electron microscopy (sem) on the original sand and themicrostructure of phosphate and the observed， the crack is the main cause of sandbetween bond bridge is easy to fracture， therefore， to improve the hardening strengthof moulding sand， improve the performance of self-hardening sand. Must try to reducethe cracks， improve the "film adhesive" and "binding bridge" of surface topography，thus improve the strength of the sand mold.Experiment studied32B6M6phosphate binder performance of precoated sand，when the environment temperature is less than20℃， humidity is less than40%RH，blowing time of120s， water vapor blowing hot air time of120s， the dry strength ofprecoated sand can reach0.90MPa， depositing strength is relatively high， up to0.72MPa， coated sand sample has good storage stability.By orthogonal experiment， found the coated sand binder theory of optimalformulation of32B8M8L10， when the environment temperature less than20℃，humidity is less than40%RH， blowing steam time is120s， blowing hot air time is120s，the dry strength of precoated sand can reach1.12MPa，storing the strength up to0.95MPa，Sand sample storage stability is good.