Oxide formed when hot metallic particles react with air during flight and on the surface, trapped as thin gray layers called stringers along splat boundaries. Content runs from near zero in VPS and cold spray to a few percent in HVOF, with the highest levels in arc and flame spray. Oxides raise hardness but cut ductility, cohesion and corrosion resistance, so specs often cap oxide content alongside porosity.
Mount shows heavy oxides in the arc-sprayed nickel, that won't pass the 5 percent limit.
Also heard as
- oxide content
- oxide stringers
- stringers
- oxide inclusions
Related terms
Splat
A single flattened, frozen droplet: the basic building block of a thermal spray coating.
Running hot
Booth talk for parameters that are overheating the particles or part; running cold is the opposite.
VPS
Vacuum plasma spray: plasma spraying inside a low-pressure inert chamber to make oxide-free metal coatings.
Porosity
The fraction of a coating's volume made of voids between and within splats, usually reported in percent.