Observation of Peek Melting Peaks within the Additive Manufacturing Material Extrusion Process in Relation to Isothermal and Non‐Isothermal Processes

The current study investigates the melting behavior of polyetheretherketone (PEEK) using both Differential Scanning Calorimetry (DSC) and Fast Scanning Calorimetry (FSC) thermal analysis techniques. The PEEK melting peaks are examined under various conditions, including isothermal and non-isothermal crystallization conditions, as well as a thermal profile mimicking the material extrusion process (MEX). The results of the analysis reveal changes in the crystalline morphology, as indicated by a shift in intensity between melting peaks crystalized at different isothermal temperatures and cooling rates. Furthermore, the behavior of the deconvoluted melting peaks differs depending on the substrate temperature during the MEX process simulation. The presence of double or multiple melting peaks suggests the presence of different crystalline populations during the manufacturing process. Understanding the formation and changes in these melting peaks can help inform the development of better printing strategies and improve the mechanical performance of printed parts.