Effect of wall structure on the dimensional accuracy of shell mould prepared by slurry extrusion-based additive manufacturing process

ABSTRACT An extrusion-based additive manufacturing process for investment casting shell mould is introduced in this paper. This process uses silica sol bauxite slurry to build shell mould. The shell mould is made up of thin walls around the casting cavity, and its additive manufacturing process is actually the building process of walls. The effect of process parameters on the dimensional accuracy of the bauxite shell mould was investigated. Taguchi’s design and Analysis of Variance (ANOVA) approach was used to evaluate and optimise the process parameters viz. wall thickness, wall height and filling pattern for dimensional accuracy. The results indicate the wall thickness, filling pattern and wall thickness are the most significant parameters affecting the dimensional accuracy in X, Y and Z directions, respectively. It is suggested that the wall thickness is set as 10 mm and the filling pattern is set as rectilinear for shell mould.