| The immediate application of this etchant to specimens of a number of aluminium materials, in particular the wrought alloys, produced, as expected, unsatisfactory results. |
| However, the market for NF3 use is growing rapidly, particularly as a plasma etchant and equipment cleaning agent. |
| Before applying the porcelain primer, phosphoric acid etchant with a cotton pellet should be applied on the base for 60 to 90 seconds. |
| Penetration of the tissue by the etchant, and hence the resulting depth of etch in the metal surface, was controlled by the degree of swelling of the gelatin. |
| The only really universal etchant for aluminium materials is Barker's method of electrolytic etching with subsequent optical microstructural contrasting in polarized light. |
| One disadvantage of this etchant is its extremely sensitive reaction to remnant deformation layers on the surface of the prepared specimen. |
