基于面积分数多尺度分析的封严涂层孔隙分布均匀性定量表征

Quantitative Characterization of Pore Distribution Uniformity of Seal Coatings Based on Multi-scale Analysis of Area Fraction

多相非均质可磨耗封严涂层的孔隙尺寸复杂、形貌不规则,采用常规方法难以对其孔隙分布均匀性进行准确的定量表征。基于面积分数多尺度分析(Multi-scale analysis of area fraction,MSAAF)结合图像二值化处理和数字图像重采样技术,利用MSAAF曲线外推拟合线斜率绝对值k与均匀性长度LH定量表征孔隙分布均匀性。引入集群系数fc,基于铝硅聚苯酯封严涂层金相照片建立具有不同孔隙分布均匀性的模型,并对孔隙面积分数为1.0%和4.6%两种情况进行数值计算,探究k和LH与孔隙分布均匀性之间的相关关系。结果表明:随集群系数fc的增大,k减小,LH增大,对应的孔隙分布均匀性变差。试验与仿真结果相比,k和LH的相对误差分别为1.6%、4.3%。该方法可以为封严涂层或其他类似材料的组成相分布均匀性定量表征提供参考。

Multi-phase heterogeneous abradable seal coatings have various pore sizes with irregular morphologies,so it is difficult to achieve quantitative characterization of pore distribution uniformity by conventional methods.In order to deal with this problem,the absolute slope k of the curve extrapolation fitting line and the uniformity length LH were obtained based on multiscale analysis of area fraction combining with image binarization treatment and digital image resampling technology.The cluster coefficient fc was introduced and the models with different pore distribution uniformity were established based on metallographic images of AlSi-polyester seal coatings.The k and LH correlated with the pore distribution uniformity were explored through numerical calculations in the two specimens with pore area fractions of 1.0%and 4.6%.The results show that as the cluster coefficient fc increases,k decreases and LH increases,and the pore distribution uniformity becomes worse.The relative error of k and LH between experimental results and simulation results is 1.6%and 4.3%,respectively.This method can provide reference for quantitative characterization of the distribution uniformity of phases in seal coatings or other similar materials.