Fabrication of Al-coated CNF reinforced aluminum matrix composite by pressureless infiltration

Al-coated carbon nanofiber(CNF) reinforced aluminum matrix composites were fabricated by pressureless infiltration at 850°C in the presence of N₂ into a CNF-Mg-Al preform. Aluminum coating on the CNF was obtained by Chemical Vapor Deposition(CVD) in order to improve the wettability and aluminum coating layer was about 10 nm on the CNF surface at 500°C and for holding time of 48 h. The effects of the preform fabrication conditions, such as pressure, temperature, and Mg contents on the infiltration were discussed. As the pressure was a 200 kPa at room temperature, the infiltration depth was largest. Moreover, Mg content was about 30% to obtain the largest infiltration depth. The ratio of non-coated to coated CNF was 0.5 to show the largest infiltration depth and the hardness and modulus of that composite including Al coated CNF were about Hv240 and 85 GPa, respectively.