icrostructure and mechanical properties of Al_4C_3 and Al_2O_3 dispersion strengthened aluminum composite fabricated by mechanical attrition and hotpressing consolidation method were studied. It was shown that fine we...icrostructure and mechanical properties of Al_4C_3 and Al_2O_3 dispersion strengthened aluminum composite fabricated by mechanical attrition and hotpressing consolidation method were studied. It was shown that fine well developed Al_4C_3 stick and equiaxed γAl_2O_3 dispersoids with total content of about 6.6 v% uniformly distributed within the Al grains or along the grain boundaries. The Al/Al_4C_3 and Al/Al_2O_3 interfaces are very clean and well bonded at atomic level, but have no fixed orientation relationships between the dispersoids and the aluminum matrix exists. At ambient and especially elevated temperatures, strength and stiffness of the composite are much higher than that of P/M Al and even better than that of the 15 v% SiCw/Al composite.展开更多
The addition of effective nucleating particles in the melt to achieve grain refinement has become the most widely used method for the casting industries.In this study,a novel GNP@MgO particle with a nanocomposite stru...The addition of effective nucleating particles in the melt to achieve grain refinement has become the most widely used method for the casting industries.In this study,a novel GNP@MgO particle with a nanocomposite structure was prepared by utilizing an in-situ reaction of the carbon source gas with Mg melt.The results showed that the particles can significantly reduce the average grain size of Mg-9Al alloy from 130.4μm to 13.1μm,and achieve an ultra-high grain refinement efficiency of 90%.The refinement mechanisms are that the Al_(4)C_(3)phase can act as a heterogeneous nucleation site forα-Mg grains due to the orientation relationship as(001)_(Al_(4)C_(3))//(002)Mg.Meanwhile,the particle distribution model shows that the velocity of MgO particles is much higher than the growth rate ofα-Mg grains.Therefore,it is pushed to the vicinity of grain boundaries during solidification,effectively limiting the growth ofα-Mg grains.The remarkable grain refinement effect was achieved through the synergistic modulation of Al_(4)C_(3)and MgO particles.This work may provide new insight into designing high efficiency grain refiners for Mg-Al alloys.展开更多
文摘icrostructure and mechanical properties of Al_4C_3 and Al_2O_3 dispersion strengthened aluminum composite fabricated by mechanical attrition and hotpressing consolidation method were studied. It was shown that fine well developed Al_4C_3 stick and equiaxed γAl_2O_3 dispersoids with total content of about 6.6 v% uniformly distributed within the Al grains or along the grain boundaries. The Al/Al_4C_3 and Al/Al_2O_3 interfaces are very clean and well bonded at atomic level, but have no fixed orientation relationships between the dispersoids and the aluminum matrix exists. At ambient and especially elevated temperatures, strength and stiffness of the composite are much higher than that of P/M Al and even better than that of the 15 v% SiCw/Al composite.
基金supported by the National Natural Science Foundation of China(grant nos.52301142,52371107,52201115)Heilongjiang Provincial Postdoctoral Science Foundation(grant no.LBH-11Z22167).
文摘The addition of effective nucleating particles in the melt to achieve grain refinement has become the most widely used method for the casting industries.In this study,a novel GNP@MgO particle with a nanocomposite structure was prepared by utilizing an in-situ reaction of the carbon source gas with Mg melt.The results showed that the particles can significantly reduce the average grain size of Mg-9Al alloy from 130.4μm to 13.1μm,and achieve an ultra-high grain refinement efficiency of 90%.The refinement mechanisms are that the Al_(4)C_(3)phase can act as a heterogeneous nucleation site forα-Mg grains due to the orientation relationship as(001)_(Al_(4)C_(3))//(002)Mg.Meanwhile,the particle distribution model shows that the velocity of MgO particles is much higher than the growth rate ofα-Mg grains.Therefore,it is pushed to the vicinity of grain boundaries during solidification,effectively limiting the growth ofα-Mg grains.The remarkable grain refinement effect was achieved through the synergistic modulation of Al_(4)C_(3)and MgO particles.This work may provide new insight into designing high efficiency grain refiners for Mg-Al alloys.
