Mechanical, Tribological, Economic and 3D Modeling Evaluation of Stir-Cast Al6061/Al2O3/Graphite Hybrid Composites as a Replacement for Grey Cast Iron Engine Valve Guides

The increasing demand for light weight and high performance materials in the automotive sector has driven the development of advanced aluminium based composite as potential substitute for ferrous alloys. The research scope included the fabrication of Al6061 composites reinforced with Al2O3 and graphite particulates using the stir casting technique, followed by extensive characterization of their mechanical and tribological properties. To ensure practical relevance, a comparative cost evaluation was also carried out. In addition a 3D model of engine valve guide was developed in AutoCAD to validate dimensional compatibility and visualize integration of composite into real world application. The result demonstrated that the hybrid composite offers superior hardness and wear resistance compared to grey cast iron, with graphite providing solid lubrication and Al2O3 enhancing load bearing capacity. The AutoCAD modeling confirmed dimensional feasibility, with economic analysis indicated the composite as cost effective alternative. The integration of experimental evaluation with 3D design modeling highlights the hybrid composite potential as a light weight, durable and economical replacement for grey cast iron valve guides, there by contributing to fuel efficiency and sustainable automotive material.