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采用多重分形理论研究半固态A356铝合金初生相,计算了其多重分形谱。结果表明,半固态A356铝合金初生相具有多重分形特征。螺旋角度为540°时,在4组螺旋角度试验中其多重分形谱宽Δα最小,初生相分布最均匀集中。浇注温度为635℃时,在4组浇注温度试验中其多重分形谱宽Δα最小,初生相分布最均匀集中。所有计算的8组试验的谱函数对称度Δf均大于0,谱函数f(α)形态都呈向左的钩状,其计算大概率子集占主要地位。多重分形谱谱宽Δα,谱函数对称度Δf和谱函数f(α)等参数可以定量表征其分布均匀性的差异,从一个新的角度去描述半固态微观组织特征。
The multifractal theory was used to study the primary phase of semi-solid A356 aluminum alloy. The multifractal spectrum was calculated. The results show that the primary phase of semi-solid A356 aluminum alloy has multifractal characteristics. When the helix angle is 540 °, the multifractal spectral width Δα is the smallest in the four groups of helical angle tests, and the distribution of the primary phase is most uniformly concentrated. When the pouring temperature is 635 ℃, the multifractal spectral width Δα is the smallest in the four groups of pouring temperature test, and the distribution of the primary phase is the most uniform. The spectral functions Δf of all the eight groups of experiments were all larger than 0, and the shape function of the spectral function f (α) showed a hooked shape to the left, which accounted for the major subset of the large probability subset. The multi-fractal spectrum width Δα, spectral function symmetry Δf and spectral function f (α) and other parameters can quantitatively characterize the differences in their distribution uniformity, from a new perspective to describe the characteristics of semi-solid microstructure.