摘要
The processing parameters and refining mechanism of Mg-Al alloy treated with a newly developed carbon inoculant under different conditions were investigated experimentally in this work.Results show that the finest α-Mg grain in AZ91D alloy can be obtained after processing at about 740 ℃,and the average grain size of α-Mg grain decreases from about 180.4 to 85.6 μ m by adding mass fraction w in = 1% inoculant into melt.However,no evident refinement was achieved with excessive inoculant for Mn-free Mg-9Al alloy.Scanning electron microscope(SEM) photo,energy dispersive spectroscopy(EDS) analysis on the Mn-contained intermediate phase and differential scanning calorimetry(DSC) results indicate that Mn element plays an important role in the heterogeneous nucleation of α-Mg grain.In the early stage of solidification,Al-Mn-C compound particles formed on the surface of Al4C3 nano-particles should be the potential nuclei for primary α-Mg and probably responsible for the grain refinement achieved in the carbon inoculation process.
The processing parameters and refining mechanism of Mg-A1 alloy treated with a newly developed carbon inoculant under different conditions were investigated experimentally in this work. Results show that the finest α-Mg grain in AZ9D alloy can be obtained after processing at about 740℃, and the average grain size of α-Mg grain decreases from about 180.4 to 85.6μm by adding mass fraction Win = 1% inoculant into melt. However, no evident refinement was achieved with excessive inoculant for Mn-free Mg-9A1 alloy. Scanning electron microscope (SEM) photo, energy dispersive spectroscopy (EDS) analysis on the Mn-contained intermediate phase and differential scanning calorimetry (DSC) results indicate that Mn element plays an important role in the heterogeneous nucleation of α-Mg grain. In the early stage of solidification, AI-Mn-C compound particles formed on the surface of Al4C3 nano-particles should be the potentiM nuclei for primary α-Mg and probably responsible for the grain refinement achieved in the carbon inoculation process.
基金
the National Natural Science Foundation of China (No. 51165030)
the Natural Science Foundation of Jiangxi Province (No. 20114BAB206021)