Title:
Synergistic Effects of Praseodymium and Antimony Additions on the Microstructural and Mechanical Properties of Al–15 Wt. % Mg₂Si Composites

Authors:
Alif Fajar Putrawan, Shazarel Shamsudin, Hamidreza Ghandvar, Nor Akmal Fadil, Tuty Asma Abu Bakar, Malaysia

Abstract:

Al Mg₂Si metal matrix composites (MMCs) are among the most promising materials for applications in the automotive industry, particularly for components such brake pads. These composites exhibit high strength, good wear resistance, excellent corrosion resistance, and low density. The incorporation of Mg₂Si particles can further enhance the properties of aluminium MMCs; however, coarse and dendritic of Mg₂Si phases are often formed during solidification due to the relatively low solidification rate. The sharp edges of primary Mg₂Si particles can act as stress concentrators, promoting crack initiation and reducing mechanical performance. To address this limitation, various modification techniques have been introduced, including alloying additions and post-processing treatments. Among the potential modifiers are praseodymium (Pr) antimony (Sb) have shown promising refinement effects. This study investigates the influence of simultaneous Pr and Sb additions on the microstructural evolution and mechanical characteristics of Al–15 wt. %Mg₂Si composites. Microstructural characterization was performed using optical microscopy and scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDX), while tensile and hardness tests were conducted to evaluate the mechanical properties of the composites. The results indicate that the addition of 0.5 wt% Pr–Sb produced the highest tensile strength of 100 MPa, representing an improvement over the unmodified composite (93 MPa). In contrast, the composite containing 2.0 wt% Pr–Sb exhibited the highest average hardness value of 100.2 HV, compared with 75.3 HV for the unmodified composite, and showed the greatest Mg₂Si particle density per unit area. The improvement in mechanical properties was attributed to the refinement and more uniform distribution of Mg₂Si particles induced by the combined addition of Pr and Sb. Overall, the simultaneous addition of Pr and Sb effectively enhanced the microstructural and mechanical performance of Al-15 wt. % Mg₂Si composites.

DOI: http://dx.doi.org/10.51505/ijaemr.2026.11404