Experimental Investigation on the Mechanical Properties of Al 6063 Metal Matrix Reinforced with Nano-Sized Calcium Derived from Cattle Bone Ash

Agro-waste has gained increasing attention as a low-cost and environmentally sustainable resource for the development of advanced engineering materials. In this study, Al 6063 alloy was reinforced with nano-sized cattle bone ash (CBA) particles to improve its mechanical and microstructural properties. Al 6063 scraps were obtained from a scrap yard, while cattle bones collected from abattoir waste were processed into nano-sized CBA particles through calcination, ball milling, and air classification under a controlled vortex flow conditions. Composite samples containing 6 wt. %, 9 wt. %, and 12 wt. % CBA were produced using the stir-casting technique. Mechanical characterization showed that the tensile strength increased from 103 MPa for the unreinforced alloy to a maximum value of 140 MPa with increasing reinforcement content due to improved load transfer and stronger matrix–particle interfacial bonding. The hardness value also increased to 88.3 HV, indicating better resistance to plastic deformation. However, the impact energy decreased to approximately 5.5 kJ/m² at higher reinforcement levels, suggesting a reduction in ductility. Microstructural analysis revealed a fairly uniform distribution of the reinforcement particles and enhanced interfacial bonding within the aluminum matrix. The findings indicate that nano-sized cattle bone ash is a promising reinforcement material for the development of lightweight aluminum matrix composites suitable for engineering applications.