Cerium in aluminum alloys

Rare-earth metals create unique opportunities in improving properties of aluminum alloys. For over a century, there have been attempts to explore cerium for aluminum alloying, emphasizing advantages it exhibits among rare earths. This review covers laboratory and industrial efforts of applying cerium for a purpose of developing aluminum alloys with superior properties. The binary Al-Ce, ternary Al-Ce-X and higher-order phase systems are reviewed with a focus on the aluminum-rich sections. The role of cerium in forming stable, high-melting-point compounds, improving strength and thermal stability is analyzed along with its function as a grain refiner in the aluminum melt, the eutectic modifier, as de-gasifying and de-slagging agent through its reaction with gas and liquid impurities. In addition to conventional alloys with cerium as a minor and major ingredient also amorphous alloys along with aluminum matrix nanocomposites, exploring cerium oxide as reinforcement, are assessed. The role of cerium in bulk alloying is expanded to surface engineering solutions enhancing aluminum wear and corrosion resistance. Efforts of cerium recovery from parts after end of service life and alloy design for a recycling friendly world are discussed to minimize losses and prevent contamination of material supply chain in modern manufacturing.