Functionally graded Nylon-11/silica nanocomposites produced by selective laser sintering

摘要

Selective laser sintering (SLS), a layered manufacturing-based freeform fabrication approach was explored for constructing three-dimensional structures in functionally graded polymer nanocomposites. Here, we report on the processing and properties of functionally graded polymer nanocomposites of Nylon-11 filled with 0-10% by volume of 15 nm fumed silica nanoparticles. SLS processing parameters for the different compositions were developed by design of experiments (DOE). The densities and microanostructures of the nanocomposites were examined by optical microscopy and transmission electron microscopy (TEM). The tensile and compressive properties for each composition were then tested. These properties exhibit a nonlinear variation as a function of filler volume fraction. Finally, two component designs exhibiting a one-dimensional polymer nanocomposite material gradient were fabricated. The results indicate that paniculate-filled functionally graded polymer nanocomposites exhibiting a one-dimensional composition gradient can be successfully processed by SLS to produce three-dimensional components with spatially varying mechanical properties.