Tool Steel Selection for Precision Electrode Slitting Blades
Precision electrode slitting requires powder metallurgy tool steels with high vanadium carbide volume to eliminate micro-chipping and maintain burr limits below 10 µm.
Galling
Meaning
Severe form of adhesive wear characterized by the localized welding and subsequent tearing of metal surfaces in sliding contact. This damage occurs when the protective oxide layer on a tool or workpiece breaks down under high pressure. In battery manufacturing, galling on slitting blades or forming dies causes surface defects on the electrode foil and ruins the tool edge.
Surface Adhesion
High frictional heat causes microscopic points of the contacting metals to bond at the molecular level. As the motion continues, galling results in the transfer of material from one surface to another, creating lumps and gouges that destroy the original geometry. The phenomenon is particularly common in stainless steels and aluminum alloys where the oxide film is easily disrupted.
Micro-welds form and then fracture as the sliding force overcomes the strength of the joint. Hardness differences between the tool and the workpiece affect the severity of the damage.
Maintenance Frequency
The presence of transferred metal on a tool surface changes the clearance and friction characteristics of the cutting operation. Once galling begins, the damage progresses rapidly until the tool is pulled for polishing or replacement. This creates unplanned downtime.
Lubrication Film
Proper selection of surface treatments and lubricants provides a barrier that prevents direct metal-to-metal contact. Because galling is sensitive to temperature and pressure, using high-performance coatings or increasing the surface finish quality can mitigate the risk. Material selection also plays a part.