Research On Investment Casting Of Turbine Blade With Gas Film Hole Based On Rapid Prototyping

This paper takes the rapid prototyping manufacturing of the air-bearing membrane turbine blades as the objet of study,which proposes the air-bearing membrane turbine blades 3D printing and casting rapid prototyping method.Besides,this paper studies the information about the reverse modeling of air-bearing membrane turbine blades,the rapid prototyping of light curing wax mold,the investment casting virtual simulation optimization and precision casting of investment casting.The main research content of this paper are as follows:First of all,the reverse modeling of the turbine blades with gas film holes.In this paper,an optical scanning technique and UG modeling technology with excellent performance for turbine blades are proposed.In the optical scanning stage,the turbine blade is scanned by XTOM educational surface scanning system.Then,the points cloud data after optical scanning is processed by Geomagic studio software.Finally,the model is imported into UG software to reconstruct the model according to the known model and the characteristic of section curve to realize the fast modeling of the model according to its own requirements.Second,in the rapid manufacture of gas-bearing film hole turbine blades.In this stage,the stereo lithography technology is used to study the process of rapid prototyping from model introduction to model making,and the factors affecting the forming accuracy are analyzed in each stage.A Fmincon function using coefficient of variation and MATLAB is proposed to obtain the optimal parameter setting in the rapid prototyping process.This stage shortens the experiment period,saves the cost and realizes the rapid manufacturing of the wax core of turbine blade.Third,the virtual simulation of the die casting of the turbine blade with gas film hole.By using the virtual simulation technology of investment casting,this paper simulates the free space curved thin wall casting process of thin wall parts,probes into the causes of the problems such as cold barrier which are easy to appear in the process of thin wall casting,and puts forward the optimization scheme to solve the problems.The technology can make up for the problems of complicated trial production,long production cycle and difficult quality control in the traditional investment casting process.In the end,the die casting of the turbine blade with gas film hole is studied.In this paper,a new investment casting scheme for small holes is proposed,and then the improved method is combined with the traditional investment casting method.According to the simulation results of the simulation technology,The design of the process is carried out in 6 stages: Casting pretreatment,shell material selection,shell preparation,shell dewaxing and roasting,melting and pouring of molten metal,and post-processing of castings.The feasibility of the scheme is verified by measuring the basic size and surface roughness of the turbine blade after casting,and the rapid manufacturing of the turbine blade with gas film hole is realized.From the research results,we can get that the investment casting method with gas-film hole blades based on the rapid development technology proposed by this project not only realizes the direct molding of the gas film hole,but also realizes the small blade parts in the realization of shorter cycle.Rapid batch production reduces the development cost,solves the problems of high cost,long cycle time,and complicated processes in traditional production,and verifies the feasibility of the process.