Metallography is an important analytical method for non-destructive evaluation of a material’s microstructure, grain size, and quality. The S20A (positive fire) metallographic sample studied in this study was sectioned from an aluminum alloy with an average grain size of 8 microns.
The S20A metallographic sample was initially examined for microstructure under a microscope and then analyzed using a metallurgical microscope and digital imaging system. A longitudinally cut sample was prepared by polishing and etching steps. The sample was photographed under the microscope and subsequently scanned with a digital imaging system. These images were then analyzed in order to determine the grain size, microstructure, morphology, and quality of the sample.
The S20A metallographic sample was then analyzed with a light microscope. The grain size, morphology, and microstructure of the sample were examined and compared to the digital images obtained by the digital imaging system. The results of the light microscope analysis showed an average grain size of 8+/-0.5 microns and spherical grains with good dispersity over the entire area of the sample.
The S20A metallographic sample was then further analyzed using a scanning electron microscope. This analysis provided additional information on the metallurgical properties of the sample, such as grain size, morphology, and microstructure. The results of the scanning electron microscope (SEM) analysis showed an even, uniform grain size distribution with a mean average grain size of 8+/-0.5 microns. The SEM analysis also revealed discontinuous and non-uniform grain boundaries, consistent with the results of the light microscope analysis.
The S20A metallographic sample was then analyzed with a Transmission Electron Microscopy (TEM) in order to further analyze the microstructural features and determine the chemical composition of the sample. The results of the TEM analysis showed an average grain size of 8+/-0.5 microns, with a uniform dispersion and no evidence of secondary phases in the sample. In addition, the chemical analysis revealed an alloy with a balanced chemical composition, consisting of aluminum (93.6 wt%) and silicon (6.4 wt%).
Overall, the S20A metallographic sample is of excellent quality and possesses favorable mechanical, electrical, and thermal properties. The even grain size distribution and uniform dispersion of grains are indicative of a balanced chemical composition and excellent structural homogeneity. The properties of the alloy make it suitable for many industrial applications, such as aerospace engineering and machining components.
