daykrolik wrote:there have been some extraordinary advances in high-temperature coatings since 1969.
Once upon a time, I was in charge of the surface science and engineering laboratory of the french nuclear energy organisation.
To instruct our case, I will gladly share two examples of unsuccessful and successful surface treatments.
The first one was the failure to elaborate a coating that would have allowed to develop industrially the process of isotopic separation of uranium vapour by laser: no material could sufficiently resist to corrosion by liquid uranium, the Mendeleev table is not expandable...
On the other hand, we could successfully develop exceptionally resistant materials to abrasion by sand, for use in military helicopter turbine blades. These were made of very thin multilayered vapour coatings of tungsten and tungsten carbide, alternating a very hard carbide and a relatively ductile metal, both refractory. The micron scale of each layer, the chemical affinity of the layers using the same metal base and the very large number of layers made the trick. I will not tell the cost...
In the case of our manifolds, I am certain that sophisticated layered materials of metal and ceramics may do the job. But at which cost? Only space or military programmes can spend big money with no concern of ROI;) I would personnally advocate a much cheaper process to recover an acceptable semi gloss look or... live with my manifolds as they stand as far as they do the job!