Effects of polyurea coating on the elastoplastic behavior of additively manufactured PLA specimens

Abstract

The fused Filament fabrication method gained its popularity in the additive manufacturing industry not only because of the low capital and manufacturing cost, but also due to its ease of production approach, availability, and mobility of the method. However, the quality of final parts and the mechanical properties are directly related to layer thickness, resolution, filament raw material, and working temperature. Thermoplastic materials, especially polylactic acid (PLA), are widely used considering their low melting temperature, lower requirement of post-processing, and sustainability. However, poor mechanical properties, layer delamination, and low ductility are the main drawbacks of these materials. This work aims to study the effects of polyurea as an elastomeric coating on PLA printed specimens. Three geometrical configurations were prepared, and tensile properties of coated and uncoated samples are investigated using stress-strain curves. It has been shown that hot polyurea coating results in a reduction in the ultimate tensile strength (UTS) of specimens. However, it increases ductility and elongation performance of the samples remarkably. In addition, the elasticity modulus and elastoplastic behavior of the specimens are modeled mathematically.