Experimental investigation of effects of build parameters on flexural properties in fused deposition modelling parts

Abstract

Additive manufacturing is a group of fabrication techniques that is used to build components by depositing material in a layer-by-layer manner. Fused deposition modelling (FDM) is one of the additive manufacturing techniques which is widely used for prototyping and production applications of thermoplastic components. In load-bearing applications, flexural and compression forces often coexist. In order to avoid failure under these loads, it is essential to study the mechanical properties of FDM components. The main focus of this research is to study the flexural properties of FDM components and to comprehend their dependence on various build parameters. It has been observed from a series of flexural tests that FDM parts have anisotropic properties and this anisotropy was not due to the material in use, but due to the fabrication process itself. In this study Ultem 9085 is used as the material to fabricate coupons with variations in build parameters including build direction, raster angle and negative air gap. A full-factorial experimental design was used to study the individual and combined effects of these build parameters on the flexural properties of the coupons. Solid and sparse-build styles were used in the coupon fabrication. Flexural properties investigated include flexural yield strength, flexural modulus, flexural strength/mass ratio and flexural modulus/mass ratio. Qualitative observation and reasoning is used to comprehend how the flexural properties are affected by the build parameters.