Particulate corrosion resistant coating composition, coated turbine component and method for coating same

An article comprising:

• a turbine component comprising a metal substrate;
• and
• a corrosion resistant coating overlaying the metal substrate and having a layer adjacent thereto, wherein at least the layer of the corrosion resistant coating adjacent to the metal substrate comprises:
• a glass-forming binder component;
• and
• a particulate corrosion resistant component adhered to the glass-forming binder component and comprising corrosion resistant particulates having:
• a CTEp of at least about 4 and being solid at a temperature of about 1300° F. or greater;
• and
• a maximum median particle size defined by one of the following formulas:
• for a CTEp of 8 or less, an Mp equal to or less than (4.375×CTEp)−10;
• and
• for a CTEp of greater than 8, an Mp equal to or less than −4.375×CTEp)+60;
• wherein CTEp is the average CTE of the corrosion resistant particulates and wherein Mp is the median equivalent spherical diameter (ESD), in microns, of the corrosion resistant particulates;
• wherein the corrosion resistant coating has a maximum thickness defined by one of the following formulas:
• for a CTEp of 8 or less, an Tc equal to or less than (1.5×CTEp)−3.5;
• and
• for a CTEp of greater than 8, an Tc equal to or less than (−1.5×CTEp)+20.5;
• wherein Tc is the thickness, in mils, of the corrosion resistant coating;
• wherein the particulate corrosion resistant component comprises bimodal particle size distribution having from about 60 to about 95% by volume of a larger particle size fraction, and from about 5 to about 40% by volume of a smaller particulate size fraction, wherein the larger particle size fraction comprises particulates having a median ESD at least about 5 times that of the median ESD of the particulates comprising the smaller particulate size fraction.