Blistering problems observed in strain induced melt activated aluminium alloys

Abstract

High temperature oxidation of aluminium alloys has been a major problem of heat treatment processes. The theory suggests that degradation as a result of long time exposure to high temperatures in the presence of water vapour results in oxidation process which releases hydrogen that diffuses into metal to form hydrogen pores; thus leading to subsurface porosity or blisters. In this study, an examination of the blister formation during Strain Induced Melt Activated process of aluminium alloys were carried out and oxides (i.e. bifilms) were found in the morphology of blisters. Thus, it is suggested that the blistering occurs in the presence of bifilms in aluminium alloys. © 2011 Indian Institute of Metals.