Heat treatment of aging hardenable aluminum alloys using secondary precipitation

摘要

"THERMAL TREATMENT OF ALUMINUM-ENABLEABLE ALUMINUM ALLOYS USING SECONDARY PRECIPITATION". The process is for the aging heat treatment of an aging hardenable aluminum alloy which has solid solution alloying elements. The process includes maintaining the alloy at a high aging temperature which is suitable for alloy aging to promote precipitation of at least one solute element, herein called "primary precipitation", for a period of time which is short relative to a T6 hardness hardness. The resulting under-aged alloy is then cooled from the aging temperature to a lower temperature and at a rate fast enough to substantially stop the primary precipitation. The cooled alloy is then exposed to an aging temperature, lower than the elevated aging temperature for primary precipitation, in order to develop suitable mechanical properties, as a function of time, by additional solute element precipitation here. called "secondary precipitation".