Friction stir processing of class 40 grey cast iron

The Advanced Materials Processing and Joining Laboratory at the South Dakota School of Mines and Technology in conjunction with the Pacific Northwest National Laboratories is evaluating feasibility of friction stir welding and processing of class 40 grey cast iron. Plunge tests were carried out with and without preheating on 0.5 inch cast iron plates using Polycrystalline Cubic Boron Nitride (PCBN) pin tools. The maximum axial force, average torque, friction factor and maximum temperature reached were plotted as a function of rotation speed and pin tool design. Metallurgical analysis of the plunges shows distinct microstructures at different regions. Micro-hardness hardness measurements were taken at those distinct regions and across the longitudinal section of the plunge.