Preparation and properties of phenolphthalein-based polyaryletherketone composite powders for selective laser sintering

Due to the problems of high material waste, numerous constraints and difficulty in achieving integrated forming in the processing of structural and microwave-absorbing integrated materials using traditional subtractive manufacturing technologies, this study focuses on the preparation and performance research of new structural and microwave-absorbing materials that could match additive manufacturing technologies. Composite powders (CIP/PEK-C) of carbonyl iron powder (CIP) phenolphthalein-based polyaryletherketone (PEK-C) are prepared by solution method. SEM is used to observe the surface characteristics of composite powders, while a rotational powder analyzer (RPA) is employed to analyze flow properties. DSC is applied to study the melting and crystallization temperature of composite powders. Additionally, the thermal conductivity and reflectivity of samples molded by selective laser sintering (SLS) are characterized. The results show that the flowability of the composite powders prepared by the solution method is related to the PEK-C content. Specifically, the Hausner ratio of the PEK-C 20% (mass fraction) experimental group is 1.24, and avalanche angle is 41.3°, which basically meets the basic requirements of SLS. The sintering temperature window of composite powders is in the range of 170-200 ℃. The SLS sintered parts exhibit certain thermal conduction and electromagnetic absorption capabilities, and the smaller the mass fraction of PEK-C, the better the thermal conduction and electromagnetic absorption effects. Among them, the thermal conductivity of the PEK-C 20% (mass fraction) experimental group is 1.02 W/(m·K), and the average reflectivity in the 8-18 GHz frequency band is close to −10 dB. CIP/PEK-C composite powder not only possesses a certain electrothermal function but also is compatible with SLS, thereby providing a new approach for the processing and forming of structural microwave-absorbing materials.