Examining the role of rare earth elements on grey iron’s microstructural and mechanical properties

Grey cast iron, prized for its durability and thermal performance in applications like engine cylinder liners, sees widespread use in defence, engineering, and transportation. Investigating the impact of rare earth elements on its properties, a mix of lanthanum and cerium was introduced. These elements act as nucleating and graphitising agents, refining graphite microstructure and adjusting pearlite layer spacing. Results showed a notable improvement in Brinell hardness (453 HB, a 79% increase with 0.6 wt.% rare earth), compressive strength (2209 MPa), and tensile strength (501 MPa at 0.4 wt.% rare earth). However, excessive rare earth inclusion can have detrimental effects. The study underscores the potential to enhance greyggrey cast iron's microstructure and mechanical properties through judicious rare earth additions.