**Abstract**

 The surface of mold steel was processed by the simple Al2O3 surface processing, and the influence of processing time on the surface morphology was studied by 3D profilometer and scanning electron microscopy (SEM). Moreover, the wettability of the Al2O3 microtextured surfaces of mold steel was also investigated. The results show that the surface morphology of mold steel varies with Al2O3 processing time. It reveals that the initial surface without any Al2O3 processing treatment behaves as a hydrophilic surface. With the increment of Al2O3 processing time, the surface roughness of the processed surface with the microtextures increases correspondingly. At the same time, the wettability of the microtextured surfaces changes from the hydrophilic to the hydrophobic. When Al2O3 processing time reaches 60 min, the contact angle reaches its maximum at which the relevant surface roughness is the minimum. It indicates that mold steel with an Al2O3 microtextured surface can be a potential application in the mold releasement.

**Keywords:** surface morphology, Al2O3, microtexture, wettability, hydrophilic, hydrophobic, processing, roughness, mold steel
