Effect of final pyrolysis temperature on the mechanical and thermal properties of carbon foams reinforced by aluminosilicate

Carbon foams with phenolic resin as precursor and aluminosilicate as reinforcement were prepared at different final pyrolysis temperatures. The microstructures, mechanical and thermal properties of the foams were investigated by scanning electron microscopy, mechanical testing and the laser flash method, respectively. The results show that the cells are mainly open with incomplete cell membranes, and the alumninosilicate particles are located in cell walls. The surface of cell openings becomes rougher as the final pyrolysis temperature increases. The ultimate compressive strength increases from 0.45 to 1.74 MPa when increasing the final pyrolysis temperature from 1100 to 1550 °C. The thermal conductivity ranged from 0.37 to 0.52 W m−1 K−1 at room temperature and decreases with increasing the final pyrolysis temperature. The occurrence of the mullite phase plays a key role in the changes of the mechanical properties and thermal conductivity of the foams.