Abstract: Additive manufacturing processes, systems and three-dimensional articles include the formation of voxels and/or portions of three-dimensional articles with different properties relative to other voxels and/or portions. The processes generally include changing one or more laser beam parameters including power level, exposure time, hatch spacing, point distance, velocity, and energy density during the formation of selected voxels and/or portions of the three-dimensional articles. Also disclosed are processes that include an additive manufacturing process that provides localized secondary heat treatment of certain voxels and/or regions at a temperature below the melting point of the three-dimensional article but high enough to effect a localized property change.