Properties of Casting Al-Cu Alloy Modified by Mixed Rare Earth (La, Ce) and its Mechanism Analyzed

Abstract

To improve the mechanical properties of casting aluminum-copper alloy, the mixed rare earth (RE) was added to ZL206 and its properties and the enhanced mechanism of alloy were researched. The results showed that the strength and hardness of the composite were improved by 10.2% and 6.2%, respectively. After adding mixed RE, which was led by the heterogeneous enrichment area blocking the growth of the α-Al phase and making grain refinement during the solidification process. The simulation results of RE surface adsorption models by first principles also showed that the elastic constant calculation improved the bulk modulus, shear modulus, and Young's modulus of the material. The addition of mixed RE enhances the strength and hardness, although it adversely affects toughness and reduces the machining index. Also, the work function decreased, and the Fermi level increased, reflecting that the electron locality on each band was strong and the bonding state of the alloy system was covalent, which showed that the corrosion resistance was enhanced after adding mixed RE. It provides a new method for the mechanism of RE-modified aluminum-copper alloys and expands the direction of cast aluminum-copper alloy modification.

Keywords

• cast aluminum alloy
• mechanical properties
• re modification
• simulation calculations
• mechanism analysis