Performance Assessment of Mechanical and Corrosion Behavior of Additive Manufactured PLA Structure for Marine Application

Abstract

Additive Manufacturing (AM) finds its applications in shipbuilding sector due to its potential to produce lightweight, customizable components and on-demand components. In the current study, PLA specimens have been fabricated using FDM based on a Design of Experiments approach. In this regard, in the current paper, the experimental study, mathematical modeling and the optimization of the PLA 3D printed structure has been discussed. The input process parameters investigated are layer thickness (LT), printing speed (PS), and infill density (ID) and the response is the ultimate tensile strength (UTS) and the specific strength. Print orientation for all specimens was horizontal with a grid infill pattern. Systematic experiments and analysis are carried out to build up the mathematical equations and explore the effect of the process parameters on the responses. Besides mechanical characterization, the corrosion performance of the 3D-printed PLA specimens was analysed in a 3.5 wt. % NaCl solution to assess their suitability for marine applications. Artificial intelligence teaching learning-based optimization (TLBO) algorithm, particle swarm optimization (PSO) algorithm and desirability function analysis (DFA) based optimization technique is used to enhance the mechanical property and response as per the requirement. Of which the TLBO showed higher precision and better global optima convergence, such as the maximum UTS (51.02 MPa) and specific strength (41.6 kNm/kg). In comparison, PSO and DFA yielded slightly lower performance. Corrosion analysis showed that samples printed with higher infill densities resulted in improved corrosion resistances and so a clear relationship between print parameters and degradation behaviour was clearly demonstrated. The work highlights the significance of the process parameter choice for the enhancement of the structure and the environmental behavior of the PLA components.