Abstract: The present work investigates the effect of the coupled thermo-mechanical phenomena that occur when applying differential cooling technology by heated and cooled forming tool segments established in functional gradation by press hardening of high strength steel to precipitation-hardenable aluminum alloy AA7075. This application aims at creating graded mechanical properties within one part by a distribution of tailored microstructures. The distribution of the detected precipitations after aging presumably influenced by the spatial variation of the contact cooling rate prior to aging is correlated to the measured sigmoidal hardness profile. Different types and morphologies of precipitates are observed at characteristic positions of the part. The formation of fine and uniformly distributed precipitates at the zones with hardness values of 180 HV is associated to the high cooling rate by low tool segment temperatures. At the same time, coarse and lath-shaped particles are detected at regions with a low hardness value of 123 HV attributed to the lower cooling rate at heated tool segments.