Solid film lubricants, corrosion

Nevertheless, there were reliable reports of corrosion occurring with molybdenum disulphide in films and in greases. Several such reports arose from the US Army , originating with a salt fog test of a missile launcher in which all parts coated with solid film lubricant rusted badly. Subsequent reports described galvanic corrosion of various metals with molybdenum disulphide in moist atmospheres. 

Gabel, M.K. and Peterson, M.B., A Study of Parameters Which Affect Corrosion Between Solid Film Lubricants and Aircraft Alloys, ASLE Preprint No. 76-AM-6C-2. 

The general limitations of bonded solid film lubricants may be summarized as follows (i) they do not last indefinitely, (ii) possibly promoting corrosion and are not corrosion preventive coatings, (iii) they have no capacity to remove frictional heat, (iv) in most cases, re-lubrication is not possible, (v) application techniques and surface preparation must be meticulously controlled or performance is jeopardized and (vi) inspection techniques are not always satisfactory [54]. 

D 2649 Test method for corrosion characteristics of solid film lubricants... 

Prevention. Fretting, because of the significant role of oxidation, is best combatted by oxidation-resistant coatings, for example, electroless nickel or softer self-lubricating coatings like silver or indium. Solid-film lubricants are also successfully employed. Additional information on prevention of fretting corrosion can be found in Chapter 2, Principles of Corrosion. ... 

The same trend was observed from a corrosion viewpoint whereas the corrosion resistance of solid film lubricants is increased to some extent by the addition of rare earth trifluorides it was considerably improved by the addition of BUC while withstanding more than 500 hours of exposure in salt spray test. 

Solid films are not generally as effective in corrosion prevention as either lubricating oils or paints, so that careful attention should be paid to corrosion-resistant materials and treatments and design features. 

Wear can result from a number of different processes, such as corrosion, metal-to-metal contact, or abrasion by solid particles. Corrosion wear can start from acidic products of combustion (Kreuz, 1969) mechanical wear from metal-to-metal contact or abrasion is normally prevented by hydrodynamic lubrication with an oil film thick enough to keep moving parts separated. 

Uses Corrosion inhibitor, lubricant, penetrant, oily film-former in aerospace, oil field, small parts, storage coatings, tubular steel, wire rope Features Allows reduced vise, at higher NV levels Properties Tan liq. or paste dens. 8.0-8.2 Ib/gal vise. 110,000-180,000 cps flash pt. (PMCC) > 105 F 58-62% solids Toxicology May cause skin irritation avoid prolonged breathing of vapors... 

Chem. Desaip. Zinc dust CAS 7440-66-6 EINECS/ELINCS 231-175-3 Uses Corrosion inhibitor, pigment in thin-film metal protective coatings, corrosion-resist, metal coatings, aerosol paints in lubricants, chemicals Features For use with either org. or inorg. binders Reguiatory ASTM Spec. D-520 Type I compliance Properties Superfine powd. 100 /. thru 325 mesh 4.5 p median particle size sp.gr. 7.0 dens. 58.4 Ib/solid gal 99.3% total zinc, 96.5% metallic zinc, 3.1 zinc oxide ZCA Zinc Dust 64L [Zinc Corp. of Am.]... 

Uses Fluorochemical intermediate for paints, coatings, printing inks, textiles, metals, plastic films and parts with low surf, energy, chem. and moisture resist., oil/grease resist., low ref. index, and surf, lubricity Properties Tan solid very sol. in acetone, MEK sol. in trichloroethylene, isobutyl alcohol m.w. 574 sp.gr. 1.7 (40 C) vise. < 7 cps (65 C) thickening pt. 30-50 C b.p. 95-185 C (50 mm) 57.2% F Precaution DOT corrosive liq. self-extinguishing Zonyl TELB-L [DuPont DuPont Canada]... 

Surfactants and polymers used in boundary Inbrication systans adsorb on solid surfaces and form a protective film. The effectiveness of bonndary lubricants has often been attributed to the adsorption affinity and the integrity of the adsorbed film. Such adsorption is inflnenced by additives incorporated into the system to reduce thermal degradation, corrosion, sludge formation, foaming, etc. There are many interactions that can take place between the additives, the snrfactants, and the base oil, leading, in addition to adsorption effects, to a number of interfacial and colloidal phenomena such as micellization, precipitation, and solubilization as well as flocculation of particulate matter in fluid [1-3]. 

Uses Film-forming rust preventive by conversion to metallic soaps oil-sol. lubricity agent by conversion of free acid to esters emulsifier or demulsifier by conversion to amine or alkanolamine soaps corrosion inhibitor Properties Solid m.w. 422 sp.gr. 0.864 dens. 7.2 Ib/gal m.p. 122 F i.b.p. 185 F flash pt. (COC) 343 F fire pt. (COC) 415 F acid no. 16 sapon. no. 32 Alox 102 [Gateway Addit.]... 

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