Rheology behavior of lubricants and its effect on the quality surface of aluminum and copper cold-drawn wires

Abstract

The roll of lubricants in the cold-drawn process is very important to obtain a good quality on the surface of aluminum and copper wires. The viscosity of a lubricant is closely related to its ability to reduce friction. When the viscosity of a lubricant is too low, the lubricated component will have inadequate protection and will therefore be subject to excessive wear. When the viscosity of the lubricant is too high, the lubricated component will expend additional energy to complete its task. In this work, the rheology behavior of traditional lubricants for the cold drawn of Al and Cu is determined from experimental data of viscosity Vs shear rate. To evaluate the efficiency of each lubricant, the roughness surface of each wire is measured by Atomic Force Microscopy (AFM). In this way a minimum of roughness in wires corresponds to the viscosity required for each cold-drawn process. It is known that different lubricants are used for the cold drawn of Al and Cu. In this work, a new lubricant developed with the aim to be used in both process is characterized by FTIR, rheometer analysis and AFM. Results have indicated that, this new lubricant with a low viscosity that promotes a lower energy process, also decreases the roughness of Al and Cu wires compared with conventional lubricants, i.e.it has an important influence in the quality of the wires surface. This means that this new lubricant could be used during the process of both metals without making important changes, which means low operations costs and flexibility for the manufacturing plant.