I just tried to be sort of linguistic here
Well, in English there are several words used for specific types of this process, as I realised.
In Russian, it's "наплавка" in all possible cases. You have to add a descriptive word to the word "наплавка" to denote a specific type.
This is why it causes confusion in translation. One has to choose one English word to translate two or more Russian words standing for the same term.
Or sometimes it's just "наплавка". What would you choose in that case. A general word "overlaying"? OR maybe "surfacing"?
Usually context is of some help, but sometimes it's just a drawing and an inscription in that drawing.
And you are staring at it and thinking what to choose.
Sooner or later you shoot and sometimes it's a bull's eye!
One more confusion arises when it's a "surface of surfacing". You use the word "surfacing" all through the text and then you encounter the "surfacing surface"... In Russian it sounds fine (no tautology), but in English it sucks...
Anyway thank you! Now it all has become much clearer to me.