Page 321 - The Tribology Handbook

~- lubricants and coatings c5
Solid

Preparation of coatings

Select appropriate coating after considering :
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1 I I 1 I
Temperature limit Life required Compatibility with Cost Supplier’s
environment recommendations

Degrease substrate (e.g.. with trichlorethylene vapour)
Removk oxides
7-
AI, Mg, Cr, Ni, Ti, steels; cu and alloys; Plistics ; Rubber
grit blast to 0.5-7 pm cla acid etch light abrasion
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Chemical conversion treatment
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Anodise Dichromate Phosphate- Phosphate- Special phosphate-
A1 4 steel, Cd, Zn fluoride, Ti stainless steels

Spray, or dip, to give 2-10 pm film after curing (trials usually needed)
Cure coating; as detailed by supplier

Specifications for solid film bonded coatings
US-MIL-L23398 Lubricant, solid film, air-drying
US-MIL-L-8937 1 Lubricant, solid film, heat-curing
UK-DEF-S1’AN 91-’9/*

US-MIL-L-46QIO Lubricant, solid film, heat cured, corrosion inhibited
US-MIL-L-8 1329 Lubricant, solid film, extreme environment
Other requirements
Satisfactory appearance
Curing time/temperature
Limits on
Film thickness
Adhesion - tape test
Thermal stability - resistance to flaking/cracking at temperature extremes
Fluid compatibility - no softening/peeling after immersion
Wear life
Performance
Load carrying capacity
Storage stability of dispersion
Corrosion - anodised aluminium or phosphated steel

c5.4