Damping Performance of Manganese Alloyed Austempered Ductile Iron

Austempered ductile iron has gained increased interest as an ideal choice of material for mechanical components exposed to dynamic loading. Apart from strength and ductility, material damping is also one of the important demands imposed on the machine components exposed to noise and vibrations. In the present study, the damping characteristics of austempered ductile iron with varying levels of Mn variations are investigated. Samples were produced with three levels of Mn variations: 0.31 wt%, 0.60 wt%, and 0.92 wt%, and they were subjected to austenitization and austempering heat treatment. Variation in the damping characteristics of austempered ductile iron were studied before and after the heat treatment by performing the impact hammer test. The microstructure and the hardness variations of the samples were studied to interpret the mechanisms associated with variation in the damping characteristics. The studies revealed that Mn addition and heat treatment contribute to the variation in the microstructure and the mechanical properties. These properties have a contribution to the variation in the damping characteristics of ADI. Additionally, the study also revealed the existence of an optimum level of Mn that could yield better damping characteristics.