**1. Introduction**

Conventionally, the surface finishing of metal molds is always done by hand lapping after processing and/or electrical discharge machining in order to attain small surface roughness without microcracks. However, in this process, operator shortcomings cause these manual processing methods to have a number of limitations. Meanwhile, consistency and repeatability are also required. Consequently, the process is extremely time consuming, which leads to high cost [1].

While automated processes suitable for the finishing of closed dies, they are limited in their application. For example, precision machining using a single point diamond tool is slow, requires conditions not readily available in an industrial environment, and is limited to flat surfaces [2–4]. Chemical micromachining and electrochemical micromachining are limited in their application and can be difficult to control [4–9]. The laser has also been widely used as a machine tool to modify the surface of the engineering materials, such as laser surface alloying, laser cladding, surface texturing, laser physical vapor deposition, laser polishing, etc. [2, 10–20].

Ultimately, surface modifications or surface treatments are vitally important for increasing service life of the critical components and devices used for engineering and structural functions. Numerous surface engineering approaches are employed such as thermal, chemical, mechanical, as well as hybrid treatments to improve or vary/change the surface finish.

In this study, the influence of alumina-based surface processing on the microtexture, morphology, and wetting behavior of mold steel has been investigated. The morphology of initial as well as processed surfaces was investigated as a function of processing time. After being processed, the influence of processing time on the surface morphology of mold steel was studied by 3D profilometer and scanning electron microscope (SEM). The wettability of the processed surface is also investigated.
