Optimization and reliability analysis to improve surface quality and mechanical characteristics of heat-treated fused filament fabricated parts

Fused filament fabrication (FFF), an economic additive manufacturing (AM) method, is largely used for the fabrication of customized components (of medical, engineering, architectural, toy, artistic, etc. industries). However, the poor mechanical and surface properties are critical barriers limiting the growth of FFF. Therefore, a novel heat treatment approach has been utilized to improve the overall performance of printed parts. The parts were made with acrylonitrile-butadiene-styrene (ABS) with three infill densities (20, 60, and 100%) and annealing was carried out by changing the levels of temperature (105, 115, and 125 °C) and time duration (20, 25, and 30 min). The experimental design was conducted by Taguchi orthogonal array while the optimization was conducted using Taguchi S/N approach. The investigated responses were surface roughness, hardness, dimensional accuracy, tensile strength, flexural strength, and impact strength. Moreover, the reliability of the mechanical properties, with higher error (α > 5%), was verified by using the Weibull statistic to determine the survival rate of annealed FFF parts for functional applications. The adopted annealing approach was found to improve the physical and mechanical properties. The SEM analysis of fractured specimens revealed the type of failure (ductile or brittle). In recapitulation, the annealing process improved the quality characteristics of FFF parts.