Influence of layer thickness on mechanical properties in stereolithography

Purpose - Mechanical properties such as tensile, yield, impact strengths, and development of residual stresses play an important role intooling applications. The objective of this paper is to investigate the effect of layer thickness - one of the influential process parameters in stereolithography (SL) process, on mechanical properties of SL components. Design/methodology/approach - Test specimens are constructed as per the ASTM standards for different layer thicknesses in SL 5000 machine, using epoxy resin CIBA tool(R) SL5530, a high temperature resistant SL material that is suitable for rapid tooling applications. Tensile, yield and impact tests are carried out with suitable equipments. Residual stress is analysed using hole drill method. Findings - The analysis reveals that when the layer thickness is smaller, the strength of the part is higher. Research limitations/implications - Conclusion of this research is drawn based on the analysis of the most widely used three layer thicknesses of 100, 125 and 150 mu m. X-ray diffraction or molecular resonance analysis may be useful to understand the reason for the variation in mechanical properties. Originality/value - This experimental study provides the useful information to the SL machine users in the selection of layer thickness to manufacture rapid tools.