A Review of FDM Process Parameters, Mechanical Properties, Tribological Behavior, and Numerical Modeling of Carbon Fiber Reinforced PLA for Bearing Applications

Abstract

Fused Deposition Modeling (FDM), also known as Fused Filament Fabrication (FFF), is widely used to produce polymeric and composite components due to its low cost, design flexibility, and relatively low material waste. Carbon fiber-reinforced polylactic acid (CF-PLA) has attracted attention for lightweight engineering applications because carbon fibers can enhance stiffness and strength while retaining the processing advantages of thermoplastic FDM. However, the performance of printed CF-PLA is strongly affected by process parameters, fiber orientation, porosity, interlayer bonding, and surface characteristics. This review synthesizes published research on the effects of nozzle temperature, printing speed, layer height, infill density, raster angle, build orientation, and carbon-fiber content on the mechanical and tribological behavior of FDM-printed CF-PLA and related composites. Particular attention is given to tensile, flexural, impact, compressive, friction, and wear behavior, as well as the potential use of CF-PLA in bush bearings and robotic systems. Numerical and finite-element modeling approaches for predicting thermal and mechanical behavior are also discussed. The literature indicates that carbon-fiber reinforcement can improve stiffness and load-bearing capability, but its benefits depend strongly on fiber distribution, orientation, interfacial bonding, and manufacturing quality