Electrical conductivity and corrosion performances of in situ and ex situ AA7075 aluminum composites

Abstract

The present study investigates corrosion behaviors and electric conductivity of AA7075 in situ (TiAl3) and ex situ (B4C) composites produced by powder metallurgy method. In production of in situ composites, various amounts of Ti (2, 4 and 6%) are added to AA7075 and for production of ex situ composites, B4C (3, 6, and 9%) are added. Prepared in situ and ex situ composite powders were pre-shaped at 600 MPa pressure with cold pressing. Pre-shaped samples were sintered in the atmosphere-controlled furnace at 580°C for 4 h. Corrosion test of produced composites was conducted in 0.1 M H2SO4 solution. As a result of these analyses, corrosion examinations on in situ manufactured composites revealed that anode and cathode currents are close to each other and those composites do not exhibit different corrosion behaviors. Corrosion rate of B4C added ex situ composites increases by B4C rate (due to increase of density of current).