Al-Ce and Al-Ce-X intermetallics are potent corrosion inhibitors

SEM image of Al-10Ce intergranular attack. Al11Ce3 acts to cathodically protect aluminum matrix
SEM image of Al-10Ce intergranular attack. Al11Ce3 acts to cathodically protect aluminum matrix 
Collection of A356-0.8Cu test bars with increasing amounts of Ce (noted in images) detailing the improvement in corrosion resistance accompanying the addition of Ce
Collection of A356-0.8Cu test bars with increasing amounts of Ce (noted in images) detailing the improvement in corrosion resistance accompanying the addition of Ce

CMI researchers at Ames Laboratory conducted the research for this highlight

Achievement

  • Electrochemical properties of Al-Ce alloys the majority binary intermetallic show highly anodic potential compared to other phases common in Al alloys.
  • Through targeted additions of Ce to A356 and other alloys it is shown that presence of Ce inhibits corrosive attack and reduces alloy degradation in harsh environments.

Significance and impact

  • Cerium is a common material and can be added directly to melts across the aluminum industry to impart improved corrosion resistance.
  • The benefits of Ce corrosion inhibition are not tied solely to the binary intermetallic and extend to higher order compositions. Creating the opportunity for compounding benefits with tailored compositional modification.
Potentiodynamic polarization sweeps of Al-Ce alloys and pure Al11Ce3 showing the high anodic potential and slow corrosion rate of Ce compounds
Potentiodynamic polarization sweeps of Al-Ce alloys and pure Al11Ce3 showing the high anodic potential and slow corrosion rate of Ce compounds