The Effect of Printing Temperature on Bonding Quality and Tensile Properties of Fused Deposition Modelling 3d-Printed Parts

Abstract

FDM 3D-printing, is an additive manufacturing technology that is being increasingly adapted in the engineering industry due to its ability to produce complex design at lower costs as the materials are thermoplastic based. Due to the nature of its sequential layer deposition, the bonding quality is highly dependent on the temperature development during printing. In this paper, an experimental investigation was conducted to study the effect of printing temperature on bonding quality with regards to dimensional accuracy and tensile behaviour of the fabricated parts. The test specimens were fabricated using PLA material at different printing temperature ranging from 180°C-240°C at intervals of 10°C. Uniaxial tensile test according to ASTM D638-14 standard was conducted at a strain rate of 1 mm/min and was repeated five times for each variable. Results show that specimens fabricated at higher printing temperature have better tensile properties. The ultimate tensile strength recorded for specimens fabricated at T=240°C and T=180°C were 36.97 MPa and 17.47 MPa respectively. Fracture surfaces were analysed and related with the tensile results to deduce the failure mechanism. The dimensions of the sample at printed different printing temperatures were measured using digital callipers and compared with the designed specification. Specimens printed at T=240°C had the worst dimensional accuracy, with a percentage difference of 10% although it yielded the highest tensile strength. The optimum printing temperature that yielded the best tensile behaviour while maintaining its dimensional accuracy was when T=220°C.