నైరూప్య

Forward Spike and Disc Forming Tribotest for the Measurement of Interface Friction in Forming

Velu R and Amala Justus Selvam

Interface friction arises during the metal forming processes. This friction force being shear in nature is the cause of many potential problems and defects. Hence, it has to be controlled by quantifying it and applying a suitable lubricant. A new tribo-test, named forward spike and disc forming test, is proposed to quantify this interfacial friction. A cylindrical billet is pressed to extrude a spike on the punch side. During the operation a disc is upset on the die side. Aluminium alloy 1100 is used as the specimen material. Simulations have been carried out for various parameters like height/ diameter ratios of the billet and spike diameters. The ratio of the height of the spike to the disc diameter is found out which is a measure of the interface friction. For different height / diameter ratios, curves have been drawn that would be used as calibration curves. From these calibration curves the interface friction arising in the forming process is measured.