Technological process of manufacturing sand core for multi-channel hydraulic valve body was described

and qualified sand core was produced by the SLS method.Through using fine pearlite sand as raw sand to prepare coated sand and adding phenolic resin with b proportion

high strength sand core can be sintered with optimized sintering parameters.Using proper spreading powder machine

the interference of spreading powder process on the sand core sintered can be decreased effectively

and pre-heating temperature during sintering process can be decreased also

which are beneficial for reducing clean difficulty of complicated sand core resulting from heat concentration and improving the precision of sand core.