As a semi-crystalline polymer, poly-ether-ether-ketone (PEEK) is a definitive alternative to metals and ceramics in engineering applications due to its excellent performance. However, its high melting temperature, viscosity and crystallization heat release induce significant residual stresses and warpages during the manufacturing process, which cannot be elucidated by experiments alone. In response to these issues, a thermo-mechanical finite element analysis model was established by comprehensively considering the types of heat transfer mechanisms, heat conduction methods and thermophysical parameters of materials, which aims to quantify how printing speed and ambient temperature govern PEEK thermal behavior, residual stress and warpage in fused deposition modeling (FDM). The predicted temperature field and warping deformation have been validated by experimental studies. Results show that temperature field distributes uniformly along the infilling direction. Increasing ambient temperature to 90 °C definitively reduces thermal gradients, stabilizes crystallization, and elevates reheating peaks, while a 60 mm/s printing speed prolongs high temperatures to enhance interlayer bonding. Residual stress features high (X, Y)-component compressive stress on external surfaces and increased Z-component tensile stress at the top surface. Higher ambient temperature and printing speed reduce warpage, with the configuration of 60 mm/s and 90 °C yielding the lowest warpage (0.34 mm). Warpage predictions agree well with experiments (85–95%), which further confirms ambient temperature’s greater role in warpage reduction. The proposed model achieves both qualitative and, in specific scenarios, quantitative predictions of process-induced geometrical distortions. These findings provide a theoretical and experimental basis for advancing FDM technique to fabricate PEEK parts with minimized warpage.
Zhang et al. (Wed,) studied this question.