低压脉冲磁场对Al-Mg-Si合金中Mg2Si相的影响

Effects of Low-voltage Pulsed Magnetic Field on Mg2Si Phase in Al-Mg-Si Alloy

以Al-13Mg-7Si合金为对象,研究了低压脉冲磁场对合金中初生Mg2Si相大小、形态、分布及合金硬度、耐磨性的影响。结果表明,低压脉冲磁场能够调控初生Mg2Si相的平均分布宽度,通过控制初生Mg2Si相在边缘的偏聚程度来提高合金表面硬度及耐磨性。在0~175V电压范围内或1~10Hz放电频率范围内的脉冲磁场作用下,合金中初生Mg2Si相的等效圆直径随着电压或放电频率的增加,均表现为持续上升趋势;当电压持续增加时,初生Mg2Si相的平均分布宽度先减小后增大,转折点为105V;当放电频率持续增加时,初生Mg2Si相的平均分布宽度逐渐减小。合金边部区域的硬度和耐磨性均优于中心区的硬度和耐磨性;各区域初生Mg2Si相的体积分数对该区域合金的硬度值起主导作用。

Effects of low-voltage pulsed magnetic field on size,morphology,distribution of primary Mg2Si phase and hardness,wear resistance of the alloy in Al-Mg-Si alloy were investigated.The results indicate that low voltage pulsed magnetic field can adjust the average distribution width of primary Mg2Si phase,and the surface hardness and wear resistance of the alloy can be improved by controlling the segregation degree of primary Mg2Si phase at the edge.In the voltage range of 0~175Vor discharge frequency range of 1~10Hz,the equivalent circle diameter of primary Mg2Si phase in the alloy presents a continuous increase trend with the enhance of voltage or discharge frequency.When the voltage is increased continuously,the average distribution width of primary Mg2Si phase is decreased at first and then improved with turning point of 105V.When the discharge frequency is increased continuously,the average distribution width of primary Mg2Si phase is decreased gradually.The hardness and wear resistance of the alloy at edge region are superior to those of the ones at the center region.The hardness of the alloy in each region is dominated by the volume fraction of primary Mg2Si phase.