Water absorption rates and mechanical properties of material extrusion-printed continuous carbon fiber-reinforced nylon composites

Abstract

Material extrusion (ME) is considered as an effective and economic method to process continuous carbon fiber (CCF)-reinforced polymer composites with complicated structures. In this investigation, water absorption tests and tensile tests were conducted on ME-printed CCF-reinforced polymer composites under hydrothermal conditions. The purpose is to meet the growing need of CCF-reinforced polymer composites for high-humidity and high-heat aerospace applications. In order to achieve optimal comprehensive performance, both the L16 (45) orthogonal array method and the fuzzy reasoning algorithm were employed to carry out multi-objective optimization of four selected input variables, including layup angle, nozzle temperature, fiber filling density, and layer thickness. Experimental results show that the comprehensive performance of composites obtained by inputting data into the fuzzy reasoning system was greater than that obtained from orthogonal test results. Specifically, the optimized input variables are 0° layup angle, 260 °C nozzle temperature, 80% fiber filling rate, and 0.6 mm layer thickness.