Study of friction during forging operation

This paper presents a review on the effect of friction during forging operation; must especially the double cup extrusion process. The metal forming process, such as forging, is one of the manufacturing processes where metal is pressed or forced under great pressure into high strength parts. Before the process, lubricant is applied to the dies in operation to promote the flow of metal, to reduce friction and wear, and to aid in the release of the finished part. Interfacial friction between the forgings dies and the work piece such as billet has a significant effect on the forging applications, forming quality, and deformation loads. The most commonly used lubricant is liquid based lubricant, such as water-based graphite, synthetic oils, liquid soap, shear butter etc. Under the high pressure condition and reductions of the lubricant film often breaks down the operation and caused poor metal flow and wears. High interface friction is a primary cause for adhesive pickup in cold forging.