The process redundancy of investment casting Cr20stirring rod with sodium silicate as binder is only 2mm.The casting defects occur such as over-size of blind hole

shell crack during pouring process

metal bean and inclusion in the stirring rod during production.Some measure were adopted to eliminate the mentioned casting defects through correcting wax pattern to control size of blind hole

adding shell layer and bundling pattern with iron wire to prevent from crack

brushing cast-type position as well as changing interval of pattern assemble and drying time of shell.