METHOD OF MAKING PRESSURE-MOLDED PRODUCT FROM ALUMINUM POWDER

摘要

A method of making a pressure-molded product from aluminum powder according to this invention consists in a fluoridizing process performed prior to nitriding process. Thus, a passive film such as an oxide film on the surface of aluminum powder turns into a fluoridized film to protect the surface of aluminum powder. Therefore, even with the lapse of time between formation of the fluoridized film and nitriding process, the fluoridized film formed on the surface of aluminum powder protects said surface in satisfactory condition and prevents an oxide film form from being formed again. Since the fluoridized film is decomposed at the time of subsequent nitriding process, N atoms acting during the nitriding process are dispersed evenly and deeply into the surface layer of aluminum powder to form a uniform hard nitride layer.