微硅粉对硅酸盐无机粘结剂砂抗吸湿性的影响

Effect of Microsilicon Powder on Hygroscopic Resistance of Silicate Inorganic Bonded Sand

研究了微硅粉附加物对新型硅酸盐无机粘结剂砂抗吸湿性的影响。试验结果表明:微硅粉的加入促进缩合反应,使无机高聚合粘结体系更复杂,减轻了外界水分对粘结网络的攻击;当微硅粉加入量为0.8%(占砂重)时效果最好,型(芯)砂试样在高湿度下存放24 h后的强度损失率由74.48%降低至19.59%;当微硅粉的加入量较少时,型(芯)砂试样内部缩聚反应虽有较大程度提高,但反应不充分、粘结网络内部硬化速度不均匀,导致水分无法及时排除,对抗湿强度造成不利影响;当微硅粉加入量过多时,造成了粘结剂的浪费,使其粘结利用率大幅降低,使得抗湿强度急剧下降。

The influence of microsilicon powder on hygroscopic resistance of the new type inorganic bonded sand was investigated.The test results showed:the addition of microsilicon powder promotes the condensation reaction,made the inorganic high polymerization bonding system more complex,and reduced the attack of external water on the bonding network.When the adding amount of micro silicon powder was 0.8%(of sand weight),the effect was the best,the strength loss rate of the molding(core)sand sample stored in high humidity for 24 h was reduced from 74.48%to 19.59%.When the adding amount of microsilicon powder was less,although the internal condensation reaction of the molding(core)sand sample had been improved to a large extent,but the reaction was not sufficient,the bonding network internal hardening speed was not uniform that caused the water couldn’t be excluded in time,and caused adverse effects on the wet strength.When the adding amount of the microsilicon powder was too more,the waste of binder was caused,so that its bonding utilization rate was greatly reduced,making the moisture resistance strength drops sharply.