CHIP MORPHOLOGY AS A NON-INVASIVE INDICATOR OF CUTTING EDGE DEGRADATION IN HIGH-FEED MILLING OF TOOL STEEL

This study examines the correlation between progressive flank wear and chip formation mechanics dur-ing high-feed milling (HFM) of DIN 1.2343 tool steel. The research compares length-based and weight-based methods for determining the chip compression ratio and shear plane angle ϕ, evaluating their sensitivity to tool degradation. Reaching the tool life limit is associated with a decreased angle ϕ, increased chip evacuation resistance, transformations in chip morphology and discoloration. Discrepancies between analytical methods are attributed to the side flow phenomenon and specific HFM tool geometries. The identified correlations enable non-invasive identification of the cutting edge condition via quantitative chip parameters, essential for eliminating micro-cracks in machined materials. In the context of manufacturing ballistic protection and structural military components, sub-sequent chip analysis allows for verifying process stability and preventing fatal component failure under extreme operating conditions in strategic applications.