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

Abstract

In 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.

The Influence of Fused Filament Fabrication Parameters on the Fracture Behavior of Pla Specimens Considering Energy Consumption

“…The technical specifications of Creality Ender3 S1 Pro and Esun PLA+ filament are given in Table 1 [21,22]. The melting point of the commercial Esun PLA+ filament is stated generally as 170-180 °C for PLA in the literature where some of the results are supported by DSC (Differential Scanning Calorimetryanalyses) [23,24]. To avoid the other influencing factors; the built orientation, printing position, infill pattern, printing temperature, and printing speed were set as constant for all specimens.…”

Analyzing the Influence of Multimaterial 3D Printing and Postprocessing on Mechanical and Tribological Characteristics

“…Details about the stages of the process are available in previous study. [16] Figure 5 presents a photograph of the sample with the highest tensile strength in this study (PLA_171), aiming to visually represent the impact of SRP on the physical appearance of the material. The discernible changes in color within the sample, as evident in the figure, vividly illustrated the effect of the process on its visual characteristics.…”

“…Although SRP is a unique and effective method for improving mechanical strength, its limitations, such as the risk of degradation of additives in the material due to repeated melting, resulting in reduced elongation at break and increased brittleness, and the potential for the roughening of the surface caused by the presence of salt serving as a mold, need to be considered. [16] Therefore, the use of different materials at each layer (multimaterial 3D printing (MM3DP)), another hybrid approach, emerges as a strong alternative to SRP. This method's primary advantage lies in its ability to harness the superior properties of two different materials, akin to the logic of composite materials, within a single material, allowing for a tailored and enhanced performance.…”