Effect of Build Orientation on Mechanical Properties of Rapid Prototyping (Fused Deposition Modelling) Made Acrylonitrile Butadiene Styrene (ABS) Parts

Abstract

Prototyping is the process of building pre-production models of a product to test various aspects of its design. Fused deposition modeling (FDM) is a process for developing rapid prototype (RP) objects by depositing fused layers of material according to numerically defined cross sectional geometry. The quality of FDM produced parts is significantly affected by various parameters used in the process. This paper aims to study the effect of one such parameter i.e., build orientation, on mechanical properties (mainly tensile and compressive strength) of FDM processed parts. In rapid prototyping (FDM), the orientation of the parts during fabrication is critical as it can affect part strength such as tensile and compressive strength. Specimens are prepared for tensile/compression test as per ASTM standards. It was found that the build orientation of the specimen has more of an impact on strength. The layering build process of rapid prototyping creates a variance in strength depending on the build orientation. The D695 standard allows for stable compression testing and is used for compression testing. Several geometries are allowed for tension specimens under the D638 standard. We chose the type I specimen as it is the most commonly used and best fit our mechanical testing equipment. From the tensile test result, it is found that when build orientation is increasing from 0° to 90°, ultimate tensile strength decreases. It is maximum at 0° orientation i.e., 15.2 MPa and minimum at 90° orientation i.e., 11.6 MPa. The tensile stress at 0° (i.e. axial direction) is 23.68 % higher than transverse direction (i.e., 90°). From the compressive test results, it is found that, when sample orientation is increasing from 0° to 90°, the ultimate compressive strength decreases. It is maximum at 0° orientation i.e., 26.66 MPa and minimum at 90° orientation i.e., 22.22 MPa. The compressive stress at 0° (i.e. axial direction) is 16.65 % higher than transverse direction (i.e. 90°).