Al 粉体への溶融 Al の無加圧浸透による AlN/Al 複合体の形成

The present study aims to confirm whether the AlN/Al composite can be synthesized or not by infiltrating molten Al into Al powder compact under N2 gas atmosphere. Firstly some amount of Al is melted in a crucible and then the same mass of Al powder with the cast Al is filled on it. The crucible has been heated at a temperature between 700 to 1150°C under the N2 gas flowing. At heating temperatures above 950°C, almost molten Al at the bottom is sucked up to the Al powder compact side forming an AlN/Al composite. The volume fraction of AlN, VfAlN, in the composite increases as an increase in heating temperature and the level of VfAlN attains to 50% at most. However, below 850°C, the power of infiltration of molten Al is not so strong that VfAlN ends in the level less than 20% but a trace of AlN formation is observed even at 700°C. The experiment indicates that a large scale contact of Al powder surface with molten Al under the nitrogen gas flow is necessary to synthesize the AlN/Al composite of a high volume fraction of AlN.