Research On Investment Casting Technology Based On Ice Mold Rapid Prototyping

Investment casting technology based on ice mold rapid forming is a new investment casting technology with low cost,wide source of raw materials and low pollution.This technology makes use of FDM process principle to make ice mold.Compared with making ice mold with silicone rubber mold,ice mold rapid prototyping technology makes ice mold with simple process,low production cost and short cycle.Therefore,investment casting technology based on ice mold rapid prototyping has a good application value in the casting of small batch or complex shape products.In order to better improve the investment casting process based on ice mold rapid forming,the following aspects are studied in this topic:(1)Design and construction of ice mold rapid prototyping experimental system.The ice mold rapid prototyping experimental system includes hardware system and software system.The hardware system includes motion system,injection system,low-temperature system,thermal insulation system,control system and dust removal system.The software system includes three-dimensional modeling software,layered software,control system software and droplet injection control software.This paper has completed the design and selection of each system,independently designed and manufactured the sprinkler head insulation device and the base plate lifting device,and built a complete and reliable ice mold rapid forming experiment system.(2)Study on ice mold rapid forming technology.Firstly,the simulation model of droplet solidification was established by using Fluent software,and the theoretical analysis and simulation study on the solidification process of the droplet were carried out.The influences of the initial temperature of the droplet and the working environment temperature on the solidification of the droplet were obtained,and the environmental temperature and the initial temperature of the droplet during the ice mold forming process were determined.Then,a mathematical model of the change of nozzle velocity is established when the moving system is accelerating,and the correctness of the model is verified by experiments.(3)Research on investment casting process based on ice mold.The ice mold was printed by the ice mold rapid prototyping system,and then the investment casting process was studied on the basis of the ice mold.In this paper,ethyl silicate hydrolysate was used as the binder of casting slurry,and the ratio of hydrolysate was calculated theoretically.Then the zirconium powder with high melting point is used as refractory material to prepare the surface layer slurry.Secondly,this paper creatively used fly ash as all refractory powder to prepare the backing slurry of the shell,and verified the feasibility of the slurry through the determination of various properties of the slurry and casting experiments.Finally,the investment casting process based on IRP technology was determined through experiments,and the metal casting with good forming effect was obtained according to this process.In this paper,a more perfect experimental system for ice mold rapid prototyping is designed and established.The mathematical model of matching spray rate with scanning rate was established,and the technological parameters and process flow of investment casting technology based on ice mold rapid prototyping were studied.This paper provides a more sufficient theoretical basis for the development of investment casting process based on IRP technology.