Investigation of the influence of salt remelting process on the mechanical, tribological, and thermal properties of 3D‐printed poly(lactic acid) materials

Abstract

AbstractIn recent years, three‐dimensional (3D) printing has become the most popular of the additive manufacturing methods. This is because fused deposition modeling has many advantages over conventional manufacturing methods, such as enabling difficult‐to‐manufacture designs, producing less waste, and so forth. However, the parts produced by this method cannot be efficiently used in machine parts due to their relatively low mechanical properties. The main reason for the low mechanical properties of these parts is the poor bonding between the layers and between the fused filaments. The objective of this study is to overcome this disadvantage by implementing a heat treatment process called salt remelting. For this purpose, a remelting process was applied to 3D‐printed poly(lactic acid) (PLA) samples by holding them in a pot filled with manually compressed powdered salt at 210°C for 45 min and then cooling them to room temperature in a furnace. The untreated and remelted 3D‐printed PLA samples were then characterized by tensile test, three‐point bending test, and hardness test to investigate the mechanical properties. The remelted samples exhibited improved mechanical properties compared to the untreated samples, and this result was attributed to the interlayer bonding and reduction of voids in the microstructure. These results were also consistent with the thermal and morphological analysis results.Highlights This study focuses on the characterization of salt‐remelted 3D‐printed PLA. Salt melt process parameters have been optimized for 3D‐printed PLA. Thermal, mechanical, tribological, and morphological properties were investigated. It was found that the salt remelting method had a significant improving effect on the mechanical properties.