超细粉末改性水玻璃对型砂性能的影响

Effect of Ultra-fine Powder Modifying Sodium Silicate on Foundry Sand

用3%(质量分数,下同)的氧化铝、氧化锌、二氧化钛、氧化镁四种超细粉体对水玻璃进行改性,在型砂中分别加入7%的四种改性水玻璃。结果表明,经超细粉末改性的水玻璃砂,具有常温强度高、残留强度低的优点。对型砂进行24 h常温抗拉、抗压强度、800℃高温残留强度测试,与未改性水玻璃相比,水玻璃砂常温抗拉强度提高了14.4%,抗压强度提高了44.3%,残留强度降低了42.9%。在此基础上,挑选出改性效果最好的氧化锌进行优化试验,氧化锌在水玻璃中加入量分别是1.5%、2%、2.5%、3%、3.5%、4%、4.5%,加入量为3.5%时,残留强度0.55 MPa,效果最优。

Four kinds of ultra-fine powder alumina, zinc oxide, titanium dioxide and magnesium oxide in modified for sodium silicate sand, were added in the sand 7% of the four modified sodium silicate. The results show that after the modification of ultra-fine powder, the silicate sand has normal temperature high strength, low residual strength advantages. For24 h of sand on under tensile and compressive strength and 800℃ high temperature residual strength test, compared with unmodified sodium silicate, sodium silicate sand room temperature tensile strength increased by 14.4%, the compressive strength increases by 44.3%,the residual strength decreases by 42.9%. On this basis, selecting the best modification effect optimize experiment, zinc oxide respectively in adding quantity sodium silicate is 1.5%, 2% and 2.5%, 3% and 3.5%,4%,4.5%, the addition amount of 3.5%, the residual strength is 0.55 MPa, the result is best.