Managing Thermal Expansion Tolerances and Yield Loss across Scaled High Speed Stamping Dies
Active thermal control and cryogenic substrate stabilization eliminate shut-height drift and thermal scrap loss in high-speed progressive stamping dies.
Tool Wear Acceleration
Meaning
Process conditions cause the edges of cutting and forming tools to degrade faster than their predicted service life. Tool wear acceleration occurs when factors like heat, friction and material hardness exceed the design limits of the tool. This phenomenon is measured by the increasing height of burrs or the change in part dimensions.
Heat Accumulation
Operating a press at speeds higher than the cooling system can handle causes the tool to soften. This thermal softening is a major driver of tool wear acceleration because it allows the workpiece material to abrade the steel more easily. Keeping the tool within its intended temperature range is the primary way to stop this.
Chemical Interaction
High temperatures can cause the workpiece material to weld to the tool surface on a microscopic level. When these welds break during the next stroke, they take small pieces of the tool with them, leading to tool wear acceleration. Specialized coatings like titanium nitride are used to create a barrier against this chemical bonding.
Mitigation Strategy
Reducing the press speed or increasing the lubricant flow can slow down the rate of degradation. Once tool wear acceleration has started, it often proceeds at an increasing rate until the tool is reground. Regular inspection schedules are adjusted based on the observed rate of wear to prevent sudden failures.