Research On Virtual Simulation And Rapid Prototyping Technology For Blade Investment Casting

Blades are widely used in the fields of aeronautics,astronautics and shipbuilding industry.Because their processing involves space freeform surfaces,traditional machining has the disadvantages of long period,complex surface machining and low qualified rate.In recent years,investment casting replaces mechanical machining on some occasions due to its near net molding.However,traditional investment casting is characterized by the need of mold design and wax injection molding,which leads to long mold design cycle.Based on rapid prototyping technology,rapid and high precision dimensionality reduction printing is insensitive to the complex and spatially irregular parts.In the paper,the combination of rapid prototyping technology and investment casting is proposed to realize the rapid manufacture of investment casting cores.At the same time,an internal collapse structure is designed to solve the molding shell fracture in the process of mold melting so that the manufacture of high precision castings in a short period is achieved.The main contents of the paper are as follows.First,according to the characteristics of a blade,its features are classified and a thirteenparameter method is used to mathematically represent the blade surfaces.Then,based on 3D CAD/CAM platform NX,a partial-parameter driven method is used to construct a 3D blade model.In addition,an internal collapse structure is designed by using different materials of different air expansion coefficients to solve the problem of shell fracture in the process of mold melting.The internal collapse structure is embedded into the 3D blade model to establish a 3D blade core model.Then,FDM rapid prototyping technology is used to 3D print the core model.After 3D printing parameters are optimized,the PLA core physical model is printed that is then postprocessed.And then,the investment casting process of the blade is designed,simulated and optimized to obtain the optimal processing parameters for blade casting.Finally,experiments are conducted to verify the process and the blades of casting precision CT4 are obtained.The research results show that the proposed process plan that combines rapid prototyping technology and investment casting can not only realize a shorter production cycle of small batch blade parts,but also saving 70% design cycle according to the standard cycle,and meanwhile can reduce developing costs greatly.It solves the traditional production problems of high costs,long cycle,complex working procedure.