3. Adhesive wear and seizure: laminating transfer layer

Every manufacturing process establishes a fundamentally asymmetrical relationship between the first two bodies, between a tool that we want to be as deformable and durable as possible, and a part that must necessarily be transformed in its shape and/or surface structure and/or volume microstructure. The first requirement almost inevitably leads to the other two. Another peculiarity of forming processes compared to other mechanical systems is that high, but not necessarily extreme, pressures (100 MPa to 1 GPa in most cases) prevail over long lengths, often tens of millimeters. Last but not least, energy dissipation is generally high, resulting in overheating, not to mention hot forming. In most cases, it is this overheating which, via lubricant operating temperature limits, limits process productivity (speed, reduction, etc.).

The predominant source of wear particles...