Laboratory and field analysis on the tribological behavior of coated and uncoated forming tools

Frequently, the life of the tools used in sheet metal forming operations is determined by a phenomenon known as galling, which originates from the adhesion of the sheet to the forming tool surface. The application of coating architectures composed by single or multiple layers of Physical Vapor Deposition (PVD) films, such as TiN, TiCN, CrN, TiCNAl, may significantly reduce the chemical interaction in the contact, up to the point that no significant adhesion may be observed for an extended number of forming operations. Usually, the evaluation of the behavior of different thin film architectures is conducted using tribometers that may or may not reproduce the conditions found in industrial practice. This work presents a tribological analysis of coated and uncoated surfaces of tools used in industrial sheet metal forming operations and discusses the capability of laboratory tests in reproducing the situations found in practice.