Laser sintering of polymer nanocomposites

Laser sintering is a commonly used Additive Manufacturing (AM) technique applicable to a variety of applications in fields such as the automotive industry, healthcare, and consumer goods. As well as offering mechanical properties suitable for end-use part production, polymer laser sintering can produce more complex structures than many other AM techniques since it does not require support structures, and parts can be stacked in the build area for more efficient processing. A wide range of polymers should theoretically be processable by laser sintering. However, in practice this is not the case, with only a small number of polymers currently able to be processed reliably and consistently. This paper reviews research that has been undertaken to increase the processability, mechanical properties and functionality of laser sintering polymers through the addition of a range of organic and inorganic nanofillers. It examines key challenges, including dispersion of the nanophase, and methods that have been developed to overcome them. The effects of the nanophase on processability are explored, as well as the importance of key processing parameters. The latest developments on techniques for production of nanocomposite powders and characterisation of parts are discussed. The final properties of laser sintered parts that have been achieved and their potential applications are highlighted, and the current challenges and potential directions for future research are discussed.