论文部分内容阅读
硼酸对用新砂配制的型砂性能的影响:硼酸增加,透气性下降,水分、强度上升,干强度上升幅度最大。硼酸对型砂性能影响是与硼酸的物理化学性能有关。用新砂混拌,水分使硼酸溶解接近成饱和水溶液,大部分湿润砂粒、粘土,并与粘土一起以簿膜形式包在砂粒表面;少部分存在砂粒、粘土间,堵死通道,降低透气性。硼酸滑腻,水溶液有粘性,故提高了湿强度和可塑性。砂型烘烤时,先失机械水,析出硼酸。在80℃硼酸开始脱水并有少量与水汽一同挥发
The effect of boric acid on the properties of sand prepared with fresh sand: Boric acid increased, air permeability decreased, moisture and strength increased, and dry strength increased most. The impact of boric acid on the sand properties is related to the physicochemical properties of boric acid. Mix with the new sand, the water to dissolve the boric acid close to a saturated aqueous solution, most of the wet sand, clay, and together with the clay wrapped in book form sand surface; Boric acid is creamy, aqueous solution is viscous, so it improves wet strength and plasticity. Sand baked, the first loss of mechanical water, boric acid precipitation. Boric acid begins to dehydrate at 80 ° C and volatilizes with a small amount of water vapor