The microstructure and mechanical properties of near-eutectic Al-12 Si alloys modified with 0-0.4% Nd（mass fraction） were investigated. The results indicate that a submicro- or nano-sized Al2 Nd phase is observed in...The microstructure and mechanical properties of near-eutectic Al-12 Si alloys modified with 0-0.4% Nd（mass fraction） were investigated. The results indicate that a submicro- or nano-sized Al2 Nd phase is observed in the modified alloy with 0.3% Nd. The morphology of the α（Al） phase is significantly refined in the Nd-modified alloys. The primary Si morphology simultaneously changes into a fine, particle-like morphology, and the morphology of eutectic Si becomes fine-fibrous instead of coarse-acicular. Relatively few growth twins are observed on the surface of the Si plate in the Al-12Si-0.3Nd alloy at the optimal modification level. The mechanical property test results confirm that the mechanical properties of the as-cast Al-12 Si alloys are enhanced after the Nd addition, with optimal ultimate tensile strength（UTS） of 252 MPa and elongation（EL） of 13% at an Nd content of 0.3%. The improved mechanical properties are attributed to the refined morphology of Si phase and the formation of the Al2 Nd phase.展开更多
基金Projects(5140521651165032)supported by the National Natural Science Foundation of China+3 种基金Project(20151BAB216018)supported by the Natural Science Foundation of Jiangxi ProvinceChinaProject(GJJ14200)supported by the Education Commission Foundation of Jiangxi ProvinceChina
文摘The microstructure and mechanical properties of near-eutectic Al-12 Si alloys modified with 0-0.4% Nd（mass fraction） were investigated. The results indicate that a submicro- or nano-sized Al2 Nd phase is observed in the modified alloy with 0.3% Nd. The morphology of the α（Al） phase is significantly refined in the Nd-modified alloys. The primary Si morphology simultaneously changes into a fine, particle-like morphology, and the morphology of eutectic Si becomes fine-fibrous instead of coarse-acicular. Relatively few growth twins are observed on the surface of the Si plate in the Al-12Si-0.3Nd alloy at the optimal modification level. The mechanical property test results confirm that the mechanical properties of the as-cast Al-12 Si alloys are enhanced after the Nd addition, with optimal ultimate tensile strength（UTS） of 252 MPa and elongation（EL） of 13% at an Nd content of 0.3%. The improved mechanical properties are attributed to the refined morphology of Si phase and the formation of the Al2 Nd phase.
