There are four problems in the application of traditional water glass to cast iron,such as slow hardening speed,sensitive to ambient humidity,low strength of sand mold(core)and poor collapsibility.Therefore,a different silicate binder was selected to study the effect of composite hardening process on the performance of specimens using ceramic sand as raw sand.First of all,the effect of microwave heating power and time on the properties of molding sand samples were studied.The microwave heating power and time has been determined on 900 W and 180 s,respectively.Then three powder additives were selected,the optimal composition is as follows:binder 2.2%,micro-silica powder 0.2%,alumina 0.2%,quartz powder 0.06%.The results showed that compared with the sand core without powder additives,the strength of 1 h sand increased to 1.86 MPa,the hygrometric strength of 98%RH increased to 1.45 MPa,the strength of 24 h increased to 2.17 MPa,and the residual strength of 800℃decreased to 0.75 MPa,The strength and residual strength of the sand at room temperature reached and approached the level of self-hardening resin sand respectively.
关键词
硅酸盐粘结剂/球形陶瓷砂/粉末改性剂/微波加热/常温强度/高温残留强度
Key words
silicate binder/spherical ceramic sand/powder additive/microwave heating/normal temperature strength/high temperature residual strength
维普
万方数据