Achieving effective interlayer bonding of PLA parts during the material extrusion process with enhanced mechanical properties

M Saravana Kumar; Muhammad Umar Farooq; Nimel Sworna Ross; Che-Hua Yang; V Kavimani; Adeolu A Adediran

doi:10.1038/s41598-023-33510-7

Achieving effective interlayer bonding of PLA parts during the material extrusion process with enhanced mechanical properties

Sci Rep. 2023 Apr 26;13(1):6800. doi: 10.1038/s41598-023-33510-7.

Authors

M Saravana Kumar¹, Muhammad Umar Farooq², Nimel Sworna Ross³, Che-Hua Yang⁴, V Kavimani⁵, Adeolu A Adediran^{6

7}

Affiliations

¹ Graduate Institute of Manufacturing Technology, National Taipei University of Technology, Taipei, 10608, Taiwan. saravana312@gmail.com.
² School of Mechanical Engineering, University of Leeds, Leeds, LS2 9JT, UK.
³ Department of Mechanical Engineering, Saveetha School of Engineering, SIMATS, Chennai, Tamilnadu, India.
⁴ Graduate Institute of Manufacturing Technology, National Taipei University of Technology, Taipei, 10608, Taiwan.
⁵ Department of Mechanical Engineering, Karpagam Academy of Higher Education, Coimbatore, Tamil Nadu, 641021, India.
⁶ Department of Mechanical Engineering, Landmark University, P.M.B. 1001, Omu-Aran, Kwara State, Nigeria. dladesoji@gmail.com.
⁷ Department of Mechanical Engineering Science, University of Johannesburg, Johannesburg, South Africa. dladesoji@gmail.com.

Abstract

The additive manufacturing technique of material extrusion has challenge of excessive process defects and not achieving the desired mechanical properties. The industry is trying to develop certification to better control variations in mechanical attributes. The current study is a progress towards understanding the evolution of processing defects and the correlation of mechanical behavior with the process parameters. Modeling of the 3D printing process parameters such as layer thickness, printing speed, and printing temperature is carried out through L27 orthogonal array using Taguchi approach. In addition, CRITIC embedded WASPAS is adopted to optimize the parts' mechanical attributes and overcome the defects. Flexural and tensile poly-lactic acid specimens are printed according to ASTM standards D790 and D638, respectively, and thoroughly analyzed based on the surface morphological analysis to characterize defects. The parametric significance analysis is carried out to explore process science where the layer thickness, print speed, and temperature significantly control the quality and strength of the parts. Mathematical optimization results based on composite desirability show that layer thickness of 0.1 mm, printing speed of 60 mm/s, and printing temperature of 200 °C produce significantly desirable results. The validation experiments yielded the maximum flexural strength of 78.52 MPa, the maximum ultimate tensile strength of 45.52 MPa, and maximum impact strength of 6.21 kJ/m². It is established that multiple fused layers restricted the propagation of cracks with minimum thickness due to enhanced diffusion between the layers.