At present,improving the properties of aluminum alloys is generally achieved by increasing the cooling rate of the melt and adding micro-nano particles.Controlling the cooling rate of the melt to improve the refining ...At present,improving the properties of aluminum alloys is generally achieved by increasing the cooling rate of the melt and adding micro-nano particles.Controlling the cooling rate of the melt to improve the refining effect of grain refiner is still a difficult problem in the aluminum alloy casting industry.An innovative and environmentally friendly casting process,known as freeze ablation,was introduced during the preparation of an Al–NbB_(2) intermediate alloy.This process significantly enhanced the cooling rate of the melt.The results indicated that the Al–NbB_(2) intermediate alloy produced under high cooling rates had a noticeable refining effect on Al–Cu alloys,with smaller NbB2 particles demonstrating superior refining performance.The average grain size of the refined Al–Cu alloy decreased from 154 to 69μm,the tensile strength increased by 12%,the fluidity increased by 18.4%,and the hot tearing index decreased from 144 to 12.The matching degree between NbB_(2) andα-Al was calculated using high-resolution transmission electron microscopy and the edge-to-edge model.It was found that the atomic interplanar spacing and the interatomic spacing mismatch between NbB_(2)’s<1120>plane and Al were both less than 10%,which further proved that NbB2 could serve as an effective nucleation site forα-Al grains to achieve grain refinement.展开更多
基金financially funded by the Fundamental Research Program of Shanxi Province General programs(No.202103021224179).
文摘At present,improving the properties of aluminum alloys is generally achieved by increasing the cooling rate of the melt and adding micro-nano particles.Controlling the cooling rate of the melt to improve the refining effect of grain refiner is still a difficult problem in the aluminum alloy casting industry.An innovative and environmentally friendly casting process,known as freeze ablation,was introduced during the preparation of an Al–NbB_(2) intermediate alloy.This process significantly enhanced the cooling rate of the melt.The results indicated that the Al–NbB_(2) intermediate alloy produced under high cooling rates had a noticeable refining effect on Al–Cu alloys,with smaller NbB2 particles demonstrating superior refining performance.The average grain size of the refined Al–Cu alloy decreased from 154 to 69μm,the tensile strength increased by 12%,the fluidity increased by 18.4%,and the hot tearing index decreased from 144 to 12.The matching degree between NbB_(2) andα-Al was calculated using high-resolution transmission electron microscopy and the edge-to-edge model.It was found that the atomic interplanar spacing and the interatomic spacing mismatch between NbB_(2)’s<1120>plane and Al were both less than 10%,which further proved that NbB2 could serve as an effective nucleation site forα-Al grains to achieve grain refinement.
