Experimental and Analytical Analysis of Light Alloy Shell Castings Using Three Dimensional Printing

Abstract

Growth of rapid prototyping (RP) technologies has proven highly significant in efforts to reduce the production time for a number of casting processes. Lot of research has been done in production of sacrificial sand moulds used in investment casting. This paper systematically presents procedure of producing shell casting using light alloys in ceramic moulds created with three dimensional printing (3DP). The shells are made using special sand provided by Z-Corporation for production of easy and economical shell moulds with creation of 3D printers. Selected part was designed using UNIGRAPHICS modeling software. The moulds using the CAD model were produced with ZCorp 510 RPT machine. An experimental and analytical investigation was conducted to establish the influence of parameters like Layer thickness (Lt), Post curing time (Pc), orientation (O) for printing of shell. Light alloy shell castings using aluminium, zinc and lead were produced with the developed moulds. The effect of other parameters like the shell wall thickness (SWT), weight density (WD) and pouring temperatures (PT) on mechanical characteristics like hardness, dimensional accuracy and international tolerance (IT) grades of castings was also analyzed experimently. The paper concludes feasibility to reduce the shell wall thickness from 12 mm to 2 mm with dimensional accuracy. Consistencies with the permissible range of tolerance grades were achieved. Further at optimised SWT 5 mm, 5 mm and 6 mm, production cost has been reduced by 54.28%, 54.28% and 49.12% and production time has been reduced by 46.05%, 46.28% and 43.42% respectively in comparison to 12mm recommended shell thickness for selected light alloys.