Process for location-specific slurry based coatings for internally-cooled component

A method of coating a turbine blade having an array of internal passageways that extend from a root to an airfoil, the method comprising:

• aluminizing the array of internal passageways within the turbine blade;
• and
• chromizing a portion of the array of internal passageways after aluminizing the array of internal passageways only up to a demarcation located at 20%-30% of an airfoil span of the turbine blade from the root such that an outer layer inboard of the demarcation of the array of internal passageways is converted to either Cr-rich gamma-Ni solid solution or gamma+alpha-Cr upon chromizing such that an aluminized section outboard of the demarcation and a chromized section inboard of the demarcation are about equal in thickness.