Study Of Making Process Of C/Al Composits With Interpenetrating Networks

The composites with interpenetrating networks have good structure homogeneous and performance; also their mechanics, calorifics and tribology arc excellent. In order lo fabricate C/Al composite with interpenetrating networks and low thermal expansion coefficient, in this paper, the making process of porous carbon was particularly analyzed, and the test brought forward the block of porous carbon in which the pores connect each other made by the technique of the pyrogenation of pitch and additives. The effect of the processing on the performance of porous carbon was analyzed. Its composite with interpenetrating networks was prepared by the vacuum gas pressure infiltration, and its thermal expansion coefficient was measured and compared with the theory value.Pitch and carbon black were used as the main raw materials, nylon 6 and cpoxy as vesicant, methyl siloxane fluid as the superficial activity. In this process, the pyrogenation was controlled at different rate of the rise of temperature for each part in air. The results show that the ratio of pore was above 40% and the distribution was well proportioned when carbon content was 50%, nylon 6 served as vesicant at 15℃ per hour. In order to enhance the ratio of pore in porous carbon, air oxidation process was made at 600℃ for 1 hour. With this process, the ratio of pore can be increased about 40%.C/Al composite was fabricated by the ZYQ250/400-12.1000 furnace of the vacuum gas pressure infiltration. Its thermal expansion coefficient was 7.94X10-6K-1 and compared with the theory values calculated by the formula of Turner. The results of the thermal expansion were much different from the values of the formula of Turner. The analyses show that inner stress in C/Al composite and cracks in carbon are the main reasons for the difference.