Carbide Nucleation Kinetics and Phase Transformation in Atomized Steels
Gas-atomized tool steel solidification kinetics suppress coarse primary carbides, enabling sub-micron MC distributions that eliminate slitting blade micro-chipping.
Shear Edge Profile
Meaning
Physical edge geometry produced during mechanical slitting or blanking of metal current collector foils dictates edge quality and burr formation risk. Inspecting the shear edge profile prevents sharp metallic projections from puncturing separator films and causing internal electrical short circuits. This quality metric applies to mechanical foil shearing, die cutting, and slitting operations while excluding laser beam cutting methods.
Cut Quality
Mechanical shearing actions leave distinct zones across metal foil cross sections, consisting of rollover, burnish, fracture, and burr regions. Analyzing the shear edge profile verifies that the burnish zone dominates the cut surface while fracture zone depth and burr height remain within micrometer limits. Clean edge profiles without structural delamination or metal slivers ensure consistent coating adhesion along electrode margins.
Clean edges reduce mechanical stress concentrations during high tension roll-to-roll web handling.
Burr Generation
Excessive clearance between punch and die cutting edges causes plastic deformation rather than clean fracture during foil cutting. Improper shear edge profile results exhibit elevated metallic burrs that extend outward from current collector edges toward active separator membranes. High metallic burrs act as sharp points that penetrate thin porous separators under stack pressure, inducing fatal internal short circuits.
Precise tool alignment suppresses vertical burr height below critical threshold limits.
Die Wear
Progressive dulling of cutting blade edges changes fracture dynamics over production slitting runs. Monitoring the shear edge profile over time signals mechanical blade wear before cut quality degrades to dangerous levels.