Analysis of the densification of a composite obtained by sintering process of aluminum bronze powders with different carbides

Abstract Aluminum bronze alloy is applied in environments that require materials of high mechanical resistance and wear, such as marine, oil & gas and aerospace ones. This study analyzes the densification of composites based on aluminum bronze with additions of the vanadium (VC) and niobium (NbC) carbides, and the influence of these carbides in the milling efficiency and improvement of the diffusion process between particles to obtain better results for density and porosity. The composites were produced by powder metallurgy from aluminum bronze powders obtained from the mechanical milling process of discarded scraps. The efficiency of the sintering process depends on parameters, such as the time and temperature of sintering, together with the size of the particles obtained from the milling process. This study aimed to obtain and characterize the composites produced by the powder metallurgy route, with NbC and VC addition and to analyze physical properties, such as density and porosity. The powder morphologies, particle sizes and samples sintered were performed by scanning electron microscopy (SEM), X ray diffraction (XRD), laser diffraction analysis and optical microscopy (OM). The results indicate that addition of VC improves the milling efficiency, when compared to NbC addition, since it promotes a greater reduction of the particle size, directly favoring the sintering process. In this case, to achieve similar particle size, twice the milling time was required when NbC was used. The density values achieve ~ 73% of reference material for VC addition and ~ 68% for NbC and porosities varying between 27% and 38%.