Evaluation of Microstructure and Mechanical Behavior of Ti p /AZ91 Composites Produced by Hot Press Sintering

Abstract In the present study, the density, morphological characteristic and mechanical properties at both room and elevated temperatures of titanium microparticle-reinforced AZ91 matrix composites were evaluated. Density measurements of the specimens indicated a close agreement between the theoretical and experimental values. Porosity was determined to be below 1% in all specimens. Morphological analyses revealed that the titanium particles were located along the grain boundaries of the matrix alloy and exhibited a relatively uniform distribution. The FESEM, EDX, and XRD analyses identified the presence of α-Mg, β-Mg₁₇Al₁₂, and Ti phases. No additional phases were detected beyond these. In this context, a pore-free microstructure devoid of secondary phases was obtained at the matrix–reinforcement interface. Compression tests revealed that both the yield and compressive strengths, as well as the ductility, were significantly improved compared to the monolithic alloy. At room temperature, the composites exhibited maximum values of 213.9 MPa for yield strength, 464.9 MPa for compressive strength, and 18.5% for ductility. These values show increases of approximately 18%, 90.5%, and 68%, respectively, compared to the monolithic alloy. Furthermore, a similar trend was observed at elevated temperatures, where the corresponding values remained significantly higher than those of the monolithic alloy. Due to their low density and superior mechanical properties at both room and elevated temperatures, composite specimens constitute a viable option for industrial applications, including the automotive sector.