The Performance And Preparation Process Research Of Fly Casting Coating

Casting coating is typically made fro m the Carrier fluid, suspending agent, binder and refractory powder and other additives.When using the coating evenly coated in the type of mold or core surface, it can improve the forming effect of casting, casting on the surface of the chemical stability and resistance to high temperature metal liquid scour. Is advantageous to the casting mold release, has the ability to protect the mold, improve the efficiency of casting shakeout and cleaning.In this paper, using ethanol as the carrier fluid, organic soil and lithium base soil mixture as a suspending agent, phenolic resin as binder, fly ash and high bauxite as refractory powder, additives including sodium carboxymethyl cellulose(CMC), polyvinyl butyral(PVB), ethyl cellulose(EC) and to disperse latex powder. Preparation of foundry coating.In this paper,we study mainly includes the following aspects:1) Developing a kind of composite suspending agent that using in casting coating of Fly ash,based on the analysis of suspension mechanism of the composite suspension agent,comparing the composite suspension agent and the use effect of the single suspending agent differences.The results showed that the use of composite suspending agent casting coating suspension is better than a single suspending agent.2) By single factor experiment,analyzes the content of various factors on the properties of coating.the results showed that:The more composite suspending agent adding amount,the higher of the suspension rate and viscosity of coating, high temperature crack resistance becoming worse. The larger the amount of re-dispersible polymer powders,the higher of the suspension rate and viscosity of coating, high temperature crack resistance becoming worse.The larger the amount of phenolic resin,the higher of the suspension rate and viscosity of coating,the The larger the amount of CMC, PVB and EC, the higher of coating suspension rate and viscosity.3) The design of five factors,four levels orthogonal experiment. The results show that: primary and secondary factors of the order of addition on the impact of the suspension rate for the EC> PVB> CMC> redispersible powder> phenol resin,Add the amount of various factors on the viscosity of the primary and secondary order phenol resin> CMC> EC> PVB> dispersible polymer powder,Excellent combination of factors for the content of phenolic resin is 3%, CMC content of 0.4%, PVB content of 1.0%, EC content of 0.9%,dispersible polymer powder content of 0.6%.4)In the process of coating preparation,the mixing process is simulated.simulating the speed flow field and pressure flow field of the six straight blade under different stirring speed.The results showed that six straight blade mixing head directly and frequently occur near the tank wall dead zone.With the increase of rotational speed,the turbulent kinetic increases,dead zone.But little effects on the increase of internal flow pattern of the rotational speed,so can not blind improve the mixing uniformity by increasing the speed.5)Under the specific speed, simulated double ribbon and six straight blade paddle-type structure was stirred flow field and pressure field inside the autoclave when mixing paint.The results showed that the double helical ribbon stirred tank fluid pulp having a large turbulent kinetic energy, very strong cast for mixing paint, coating of various performance indicators meet the requirement. S howing very dense coating structure, coating integrity is good.