PRODUCTION AND CHARACTERIZATION OF AA 7075 METAL MATRIX COMPOSITES REINFORCED WITH RED MATTA RICE HUSK BIOSILICA

The effects of adding heat-treated biosilica made from red matta rice husk to Aluminum-7075 series alloy metal matrix composites are examined in this study. The matrix was created using the stir casting technique, and the specimens were subsequently characterized in accordance with American Society of Testing and Materials (ASTM) guidelines, covering mechanical, fatigue, wet and dry sliding behavior, and creep strain characteristics. The improved mechanical and fatigue properties of AB2 (Aluminum-7075 series alloy with 3wt.% of biosilica) make it a superior material composition among all the other designations. The improved tensile strength of 540MPa, yield strength of 234MPa, impact energy of 23.3J, and fatigue strength of 313MPa were noted. In contrast, AB3, which has a 5wt.% of biosilica content, offered higher wear resistance and less creep strain in both dry and wet sliding environments. For example, AB3 shows a specific wear rate of 0.008mm3/Nm and a coefficient of friction (COF) of 0.49 when dry sliding wear is applied. In wet sliding wear, the COF is 0.49 and the specific wear rate is 0.007mm3/Nm. Additionally, AB3 exhibits creep resistance values of 0.0192, 0.0246, 0.0984, 0.211, and 0.369 at 2000, 4000, 6000, 8000, and 10,000s, respectively. The biosilica, derived from the husk of red matta rice, performed well as the reinforcing agent and advanced the matrix's capacity for load transfer and microstructural stability. This study highlights how biosilica-reinforced AA7075 composites could be used in applications requiring higher mechanical strength, fatigue performance, and wear resistance. The results offer significant perspectives for the development of materials with improved overall performance standards.