Microstructural Index to Quantify Thermal Spray Deposit Microstructures Using Image Analysis

The basic metallographic analysis leads to qualitative interpretation of the structural characteristics of a microstructure, for example the presence of phases, and the description of singularities such as inclusions. On the contrary, microstructural characterization which implements image analysis leads to a quantified analysis of structural characteristics. A method is described to assess thermal spray deposit microstructures using image analysis by means of a metallographic index. This index is based on the determination of several stereological and morphological parameters by primary referee to the size-shape distributions of the features, the fractal dimension of the deposit upper surface, and the Euclidean distance map of the bodies of interest. This work employs quantitative metallography on a much wider scale to provide better quality control of deposit microstructures.