Primer thermal sprayed underlayments, useful as surface
preparation tools, perform an anchoring function for subsequent
overlayments. They are typically, but not always, “self-bonding”,
that is they are metallurgically bonded to the substrate in the
as-sprayed condition. Self-bonding materials include:
· Pure molybdenum
· Pure tantalum
· Pure niobium
· Nickel-aluminum alloys and composites
· Nickel-chrome-aluminum alloys and composites
· Nickel-chrome-aluminum-cobalt-yttria composites
· Nickel-chrome-aluminum-molybdenum-silicon-boron-iron-titania
composites
· Nickel-chrome-aluminum-molybdenum-iron composites
· Exothermic MCrAlY’s
Mechanical or non-metallurgical bond coats include:
· Nickel-chrome alloys
· Nickel-chrome-iron alloys
