LM-6 alloy is an eutectic alloy of aluminum and silicon as major constituents. This alloy contains 10 to 13% by wt of silicon. This is widely used in automobile and aircraft industries, due to its high strength to weight ratio, excellent corrosion resistance and least expansion nature. These alloys are best suitable for large, intricate and thin walled castings in sand and metal moulds. Modification is a chemical process adopted to strengthen this alloy. Sufficient literatures are not available to enlighten us the properties of this alloy with modification and modification with vibration using a mechanical stirrer. So the present work is carried out to study the changes in properties of this alloy by modification and modification together with vibration using a stirrer. Stirring is done before pouring in to the mould. Sodium is used as modifier. Test bars are cast at different conditions and compositions and their properties such as ultimate tensile strength, hardness, and microstructure are studied. All the test bars are made according to British standards. Test results reveal that modification results an overall improvement in the properties. Further vibration through stirring improves the mechanical properties. Stirring time and speed of stirring are also influence the strength of LM6 alloy. Microstructure analysis reveals that fibrous structure is predominant in modification and grain refinement is predominant in stirring.
