. EFFECT OF CARBON NODULES ON CONTACT ANGLE OF AUSTEMPERED DUCTILE IRON (ADI) Sonu Praneeth Gandam, Sourav Das, Dr. Pradeep Rohatgi Department of Material Science and Engineering., UW-Milwaukee. Introduction The Austenitic Matrix of Acicular Ferrite known as Ausferrite which makes up the microstructure of ADI. Austempered Ductile Iron [ADI] provides a range of high strength irons with higher ductility and toughness. Properties: Tensile strength: twice that of ductile iron Wear resistance: superior to steel, ideal for high abrasion applications Weight: 10% lighter than steel Cost: easier to machine than steel, reduces machining allowances Results: In this work the effect of carbon nodule count and carbon nodule size on contact angle with three grades of Austempered Ductile Iron, ADI 900-1200-1600, have been studied. ADI-900: minimum carbon nodule count per area, minimum carbon nodule area ADI-1600: maximum carbon nodule count per area, maximum carbon nodule area ADI-900 show maximum water contact angle since it has minimum carbon nodule count and area. Surface energy determines the contact angle. ADI 900 has higher surface energy as it has low amounts of carbon nodules. ADI 900, 600 grit size show maximum contact angle Conclusions A relationship exists between the carbon nodules count and the grade of ADI More the carbon nodules area and count more is the wettability of the Austempered Ductile Iron. Roughness effects the contact angle, maximum observed at 600 grit. Scope for Future Work: Design of microstructure showing hydrophobic properties. Investigating the corrosion behavior and correlating it with carbon nodule count and microstructure Figure 1. Heat Tinted Microstructures of: (a) ADI-900 (b) ADI-1200 (c) ADI-1600 (a) (b) (c) Etched Microstructures of: (a) ADI-900 (b) ADI-1200 (c) ADI-1600 Methods (a) (c) (b) Literature cited D. Shi*, D. Li, G. Gao and L. Wang “Relation between Surface Tension and Graphite Shape in Cast Iron” Materials Transactions, Vol. 49, No. 9 (2008) pp. 2163 to 2165 M. Kaczorowski, A. Krzyńska, “Mechanical properties and structure of austempered ductile iron(ADI)” Archives of Foundry Engineering, Volume 7 Issue 1/2007, 161–166. Acknowledgments We acknowledge gratefully the support of the NSF Fundamental Project-1331532 and NSF I/UCRC for a water equipment and policy grant for this work. Samples by: A. Sinlah, D. Handayani, R. C. Voigt, K. Hayrynen, R. M'Saoubi & C. Saldana “Effects of microstructure and strength on wear performance in rough milling of austempered ductile iron” International Journal of Cast Metals Research Acknowledgments This Project was funded by NSF Applied process