| Stereolithography(SLA)is one of the 3D printing technologies that can obtain a three-dimensional model or product without a tooling.Investment casting is a technique in which several layers of refractory material are coated on the surface of a fusible pattern,and the pattern is removed to obtain a ceramic shell for casting.In this paper,the process and materials used in SLA 3D printing for rapid investment casting are studied,metal casting products are obtained quickly with low cost by using SLA 3D printing technology.The issues of the shell cracking encountered in current process and the inability to apply to titanium alloy have been studied.Using a special resin for investment casting,a pattern with a lightweight structure is printed by SLA process,combined with the traditional pattern assembly,shell building and dewaxing process,and the SLA model remaining in the shell is burned at a high temperature.After that,a ceramic shell which can be used for casting is obtained.The main research results of this paper are as follows:(1)Combining SLA 3D printing with investment casting technology,the SLA-based rapid investment casting process has been developed.The castings produced by this technology have the advantages of high dimensional accuracy,smooth surface,high detailed features and environmental friendly.It can greatly reduce the product development cycle and cost,and significantly enhance the competitiveness of enterprises.(2)The method of processing the model into a honeycomb lightweight structure that does not expand the shell,saves raw materials,and reduces ash residue is studied.(3)The shelling building process was studied,and the process parameters of silica sol shelling,reinforcement,dewaxing,and pattern burnout were verified.(4)Optimized the SLA resin formulation for investment casting.Low viscosity contributes to increased void ratio and low ash content guarantees the quality,no contain of heavy metal Sb can be used for titanium alloy casting. |
PDF Full Text Request