Additive Manufacturing of Ceramics Enabled by Flash Pyrolysis of Polymer Precursors with Nanoscale Layers and oxidation resistance of final composites

C/C and C/SiC show excellent mechanical properties and thermal shock resistance even at high temperature, for these reasons they are the most used materials for aerospace applications, such as nose cones, leading edges and rocket nozzles. The key impediment to additive manufacturing of net shapes from Polymer Derived Ceramics (PDCs) has been the very slow heating rates with a process period of about 10 h, which are required to preempt fissures in the ceramic caused by shrinkage, and to allow small molecules (e.g. hydrogen, ammonia methane etc.), as the polymer evolves into the ceramic phase, to escape. For these reasons, the infiltration of fiber preforms from the polymer route, by the process known as polymer-infiltration-pyrolysis (PIP) is difficult. An additive manufacturing novel design has been developed at Colorado University to achieve CMCs via preceramic route by reducing the time for pyrolysis to about few seconds (the so-called flash pyrolysis).