Replacing Thermal Sprays

The various types of thermal spray coatings, including HVOF (High Velocity Oxygen Fuel), are created by melting a feedstock material — usually a metal, alloy, carbide or ceramic — and spraying it onto a part, creating a molten coating. Thermal sprays can produce thick, dense coatings with strong bond strengths, but these coating processes also have certain fundamental challenges…

The problems with thermal spray coatings

The greatest drawback for thermal spray is usually cost. Thermal spray is applied most often by a robot, which must be programmed for the specific part to be coated, and frequent adjustments must be made for parts with complex geometries. Unlike chrome plating which coats an entire surface at once, thermal spray is usually applied to an area about three quarters of an inch wide at one time. For large, simple surfaces thermal spray may be applied more cheaply than chrome; but for complex geometries thermal spray processing is considerably more expensive.

Another fundamental limitation of thermal spray is that it is a line-of-sight coating process. For parts that lie outside the line of sight, such as inner diameters beyond a couple of inches, other coating methods must be used. And in addition, thermal spray coating usually requires a further machining step to achieve critical dimensions, which adds further time and expense.

The advantages of Duralar

Duralar can provide hard coatings with strong bonds that are superior to thermal spray. With its unique, multilayer, nanocomposite blend of metal and diamond coating material, Duralar can provide not only greater hardness and longer wear but also superior corrosion and erosion resistance. And it can accomplish all this with a faster, simpler, more streamlined process that requires no final machining to achieve precise tolerances. All of which is why Duralar can deliver a better hard coating at a more attractive price — a superior replacement for thermal spray coating.