Production and investigation of properties of al7075 alloy matrix composites with waste glass and carbon fiber powder additives by powder metallurgy method

In this study, Al7075 aluminum alloy was supplied in powder form and reinforced with waste glass and carbon fiber powders. The reinforcements were added at weight fractions of 4%, 8%, and 12%, and the composites were fabricated using the powder metallurgy (PM) method. Prior to fabrication, the powders were mechanically mixed for 1 hour, then placed into 20 mm diameter molds, compacted under a uniaxial pressure of 300 MPa, and sintered at 600 °C. Both single (glass or carbon fiber) and hybrid composites were produced using this method. The effects of reinforcement ratios on the hardness and wear behavior of the materials were investigated. Hardness tests indicated that both glass and carbon fiber reinforcements increased the hardness of the Al7075 alloy, while in hybrid composites, hardness varied among the single composites. Wear tests revealed that composites produced with carbon fiber exhibited lower wear, however, partial plastic deformation was observed at low reinforcement ratios, while partial particle detachment occurred at high reinforcement ratios. Therefore, wear tests were not conducted for hybrid and high-carbon fiber composites. Only the glass fiber reinforced composites, which provided better and more consistent results, were subjected to wear testing, X-ray diffraction (XRD) analysis, and surface characterization using scanning electron microscopy (SEM). The wear tests demonstrated that glass fiber reinforcement significantly improved not only the hardness but also the wear resistance of the composites. As the reinforcement ratio increased, the friction coefficient and wear rate decreased. While an increase in rotational speed reduced both the friction coefficient and the wear rate, an increase in applied load decreased the friction coefficient but increased the wear rate. XRD analyses revealed the amorphous structure of the glass fibers and showed that the reinforcement did not alter the crystal structure of the alloy. SEM images indicated that fiber reinforcement reduced deep grooves and deformation traces on the surface and mitigated mechanical wear effects through matrix debris and oxidized regions. Keywords: Al7075, Metal Matrix Composite, Powder Metallurgy, Glass Fiber, Carbon Fiber, Hardness, Wear.