Morphology Evolution of Mn₅Si₃ Phase and Effect of Mn content on Wear Resistance of Special Brass

There is a surge of interests in developing newer materials with special properties and many areas are being explored by several groups. We wish to report our findings on the effect of Mn content on the microstructure and tribological behavior of special brass. With the increase of Mn content in the range of 4–10 wt%, the hardness and wear resistance of the special brass were all changed, and the adhesion with abrasion is form the friction behavior, mainly for all brasses. It was observed that the matrix grain size was the smallest, and the hard phase was precipitated the most when the Mn quantity attained the 8 wt% mark. During this period, the brass has the highest hardness and best wear resistance, which results from the grain refinement and load transferring effect of precipitates. It was characterized by SEM, EDS, XRD, TEM, etc., and the results confirmed that the precipitates were Mn₅Si₃ and its structure was hollow hexagonal prism. The morphology evolution of the hard phase and its growth mechanism have been investigated, analyzed and simulated the nucleation and growth process of the Mn₅Si₃ phase based on crystallography. The outcomes also showed that the presence of defects on the {0001} faces was the crucial factor for one-dimensional elongated structure of Mn₅Si₃ phase.