Page 38 - PCMI Journal July 2018

David Allen | Emeritus Professor | Cranfield University | UK Photochemical Machining of Aerospace Materials
Issue 131 July 2018 PCMI Journal 37
5/31/18
Anodising of aluminium through photoresist stencils
Dyes and pigments can be incorporated into the porous oxide surface layer and sealed within it to form:
• Decorative finishes or
• Colour contrasts to emphasise
alphanumeric data, such as: • logos,
• code numbers,
• bar codes
• identities etc.
Helicopter air intake grille
Etchability ratings of metals and alloys
(modified from PCMI publications)
Good
Good to fair
Fair to poor
Poor
Copper
Ppt. hardening s/s
Molybdenum
Tungsten
Copper alloys
Martensitic s/s
Nichrome (Ni, Cr)
Hastelloy C
Zinc
Ferritic s/s
Vanadium
Titanium
Carbon steel
Austenitic s/s
Chromium
Rene 41
Kovar (Fe, Ni, Co)
Inconel (Ni, Cr, Fe)
Gold
Niobium
Nickel
Hastelloy B
Lead
Tantalum
Nickel alloys
Manganese
Magnesium
Rhenium
Aluminium
Zirconium
Anodised aluminium
4