Contact phenomena and surface layer evolution in micromilling of AISI H11 induced by synthetic flank wear

The production of miniaturized components imposes strict requirements on dies and molds, demanding tailored surface integrity to enhance fatigue performance and tool life. Micromilling is widely used due to its high dimensional accuracy and excellent surface quality, while also affecting near-surface mechanical properties. Progressive tool wear modifies cutting-edge microgeometry, influencing engagement conditions and forces. This study employs a deterministic approach to isolate the effects of flank-face modifications at the minor cutting edge during micromilling of hardened AISI H11 tool steel. Results show that increased contact area intensifies tribological interactions, causing thermo-mechanical compression that alters surface-layer microstructure, increasing microhardness and compressive residual stresses.