Grain boundary segregation of alloying Cu induced intergranular corrosion of B4C-6061Al composite

The intergranular corrosion (IGC) and the microstructures in B4C-reinforced 6061Al composite were investigated in the present work. IGC only occurred in the Cu-containing samples. The artificial aging decreased the IGC resistance of the composite. Corrosion propagated through the aluminum grain boundaries as well as the B4C/Al interfaces. The microstructures characterizations by transmission electron microscopy (TEM) indicated that a continuous Cu-rich layer with width of 3.5 nm along grain boundary was responsible for the IGC susceptibility of aged Cu-containing sample.

Automated summary

In this study, intergranular corrosion (IGC) in B4C-reinforced 6061Al composite was investigated, showing that IGC only occurred in Cu-containing samples. Artificial aging was found to decrease the resistance to IGC in the composite. Transmission electron microscopy (TEM) characterization revealed a continuous Cu-rich layer along the grain boundaries responsible for the IGC susceptibility of aged Cu-containing samples.