Preparation of Al₂O₃k/Al materials by counter-gravity infiltration casting

Al₂O₃k/Al materials without obvious macro casting defects were produced using alumina bubble brick as pore-forming materials through the counter-gravity infiltration casting system. The results show that along with the increase of the metal temperature and hollow balls preheating temperature and the particle size of hollow balls, the length of infiltration is getting longer. Besides, along with the increase of the particle size of the hollow ball, the void content decreases. Improving the filling and holding pressure, lengthening the holding time and adding metal Mg are the effective measures to improve infiltration process.