Mechanical and tribological properties of the hybrid metal matrix composite Al/Al₂O₃ particles/Al₂O₃-SiO₂ fibers

The mechanical and tribological properties of a new generation of hybrid metal matrix composite (HMMC) reinforced with alumina (Al₂O₃) particles and aluminosilicate (Al₂O₃-SiO₂) fibers were investigated. The material was produced using the vacuum infiltration method, in which a porous ceramic preform was infiltrated with liquid aluminum under vacuum conditions. Various fiber contents were tested to assess their influence on mechanical and tribological characteristics. Tensile strength was measured, and it was observed that the highest strength was achieved with 3.66% fiber content, while further increases in fiber content led to a reduction in strength. Hardness was also examined using the Brinell method, and a general improvement compared to the aluminum matrix was noted, although no clear correlation with fiber content was found. Tribological tests were conducted using the a pin-on-plate method, and friction coefficients were recorded. The wear mechanisms were analyzed, revealing the presence of both abrasive and corrosive wear. The study revealed that the incorporation of aluminosilicate fibers enhances the mechanical properties of the composite up to an optimal content, beyond which further addition leads to a deterioration in performance. These findings indicate that careful optimization of fiber content is essential to achieve a balance between mechanical strength and wear resistance.