An evaluation of the shape-memory behavior and mechanical properties of polylactic acid/Ni80Cr20 continuous wire composite produced by extrusion-based additive manufacturing and in-melt simultaneous impregnation method

Abstract

This study evaluates the mechanical and shape-memory properties of PLA/Ni80Cr20 continuous wire composite materials. The samples were produced using an extrusion-based additive manufacturing (AM) process with in-melt simultaneous impregnation of metal wire, followed by 3D printing. The reinforced samples were fabricated using metal wires of 0.1 and 0.15 mm in diameter and 5 and 10% volume percentages. The maximum mechanical (tensile and flexural) properties were obtained in the reinforced samples with a 10% volume percentage of metal wire of 0.1 mm in diameter. The samples exhibited a maximum ultimate tensile strength of 116 MPa, a maximum tensile modulus of 11.7 GPa, a maximum flexural strength of 221 MPa, and a maximum flexural modulus of 17.8 GPa. This research used a novel method to investigate the shape-memory properties of PLA. By applying a potential difference to the samples, the heat generated by the metal wire was absorbed by the matrix polymer, which increased the temperature of the material. This increase in temperature resulted in a change in the samples' shape. The effect of voltage on the wire was investigated, and a voltage of 40 V was applied to the U-shaped samples with special fixtures to measure the shape recovery and shape stabilization percentage. Based on the final results, it can be deduced that 3D-printed composite materials, along with appropriate wire type, wire diameter, voltage, and uniform temperature distribution, can be used as shape-memory materials for a wide range of applications with desired temperature conditions, especially in cases where direct heat cannot be applied to the sample.