Research On 3D Printing Process Of Wax Pattern For Investment Casting

With the development of industry,the performance requirements of products are higher and higher,and high requirements must be accompanied by high costs.For small batch,such as aerospace components and products in the initial development stage,the cost is high.In order to solve this problem,it is necessary to put forward a new manufacturing scheme to break the traditional one.At this time,rapid manufacturing technology came into being.Rapid manufacturing technology not only reduces the production cost,but also shortens the manufacturing cycle of product research and development,but also has a variety of problems,such as high cost of laser sintering,poor precision,toxic light curing,etc.In view of the above problems,this paper proposes a rapid investment casting technology,which combines melt deposition with investment casting,and obtains high-precision products by printing high-precision wax pattern combined with casting technology.This paper combines the advantages and disadvantages of other rapid prototyping technologies,and designs a 3D printing system for investment casting.Firstly,this paper explains the working principle of the system,builds a three-axis motion platform,and uses ANSYS to analyze the thermal stability of wax supply tank,wax conveying hose and printing nozzle,and puts forward corresponding insulation measures to verify its rationality.Secondly,the molding properties of the wax were tested,and the relevant parameters were obtained,such as melting point of 67 ?,tensile strength of about 5MPa,hardness of2.09hv4.9 and linear shrinkage of 0.25%.In order to show the formability of casting wax,the line surface body printing was carried out,and the results met the expected requirements.Then,the difference between the actual line width and the ideal line width is used as the experimental result to obtain a better combination of printing parameters.For example,the air pressure is 0.16mpa-0.22 mpa,the nozzle diameter is 0.4mm-0.8mm,the nozzle temperature is67 ?-70 ?,the moving speed is 25 mm / s-35 mm / s,the distance between nozzle and substrate is 0.4mm-0.7mm.Through the orthogonal test,the optimal combination of parameters is obtained,that is,the air pressure is 0.18 mpa,the nozzle diameter is 0.6mm,the nozzle temperature is 68 ?,the moving speed is 30 mm / s,and the distance between the nozzle and the substrate is 0.5mm.The influence degree of process parameters is:temperature > nozzle diameter > air pressure > moving speed > distance between nozzle and substrate.This parameter can get good quality wax line,and can be used as the process guidance to improve the molding process,which provides technical support for the follow-up high-quality wax printing.Finally,using the above process parameters for 3D solid printing,the influence of lamination thickness,filling density and preheating temperature on the dimensional accuracy of printed parts is analyzed,and the interaction among the three factors is studied.The results show that the optimal process parameters are: lamination thickness 0.6mm,filling density20%,preheating temperature 40?.