Study Of Metal Mold Casting Coating For Magnesium Alloy

Magnesium alloy aslight metalstructure material,are widely used inaerospace,transportation,3C and other products,the one of forming method ismetalmoldcasting.The performance of metal coating determines the quality castings,coatingsneed high strength, adequate viscosity and leveling etc..According to the properties ofthecoatingschoice aggregate,suspending agent, adhesive, the carrier liquid, flameretardant etc..This paper studies two kinds of coatings,one use magnesiapowderanddiatomite as aggregate, another use bauxite and talcum powder as the aggregate.Themain research contents are as follows:Magnesium powder coating: the proportion ofmagnesia powder and diatomite,carrierliquid (water) quantity,and Join the range of sodiumbentonite, CMC, waterglass,hexametaphosphate got bysingle factor.Through orthogonaltest,got the best proportionof thecoating,The coating has goodstrength, viscosity,suspended.Bauxite coating: the ratio forthe bauxite andtalcumpowder,carrierliquid (water) quantity,andJointhe range of sodiumbentonite,CMC,waterglass,hexametaphosphate got by single factor.Through orthogonaltest,analysis of range incompositionoptimization,detection of the coatings performance,determine the best formulation of the coating.Preparation process for two kinds of coating,First CMC with sodium bentoniteslurry made of composite suspensions,water glass and hexametaphosphate made ofcomposite binder;In aggregate-suspending agent–adhesive for sequential loading.Usingthe method of the blade mixing preparation coatings.Magnesia powder coatings in650r/min speedmixing,Bauxite coatings in500r/minspeed mixing;stirring1.5hours.Magnesium alloy melting process easy oxidative combustion, by using thesmelting magnesium alloy covering agent protection, simple operation and good effectof melting.The casting coating have good quality,not dripping,after casting castingsurface smooth no flow marks,no oxidationblackening,Coating without seriousloss,show that the coating has good performance and can be used in the actual production.