Hypereutectic Al–Si alloys are increasingly being as used as lightweight materials for engine components. This study is focused on understanding the tribochemical performance of a cast iron/Al–Si alloy system lubricated in the boundary regime using lubricating oils containing Zinc Dialkyldithiophosphate (ZDDP) and different friction modifiers. The tribological performance of two organic and two inorganic Mo-containing friction modifiers, blended in a ZDDP-containing oil, is evaluated on a Plint TE 77 reciprocating tribometer in contact conditions comparable to the conditions in a piston ring/cylinder liner system of an internal combustion engine. Surface sensitive analytical techniques such as secondary ion mass spectrometry, X-ray photoelectron spectroscopy, and Raman spectroscopy have been used to determine the chemical nature of the tribofilms formed on the Al–Si material. The additive effects on tribofilm formation as well as tribological performance are discussed.
This study shows that the Mo-containing additives, when blended into a ZDDP-containing lubricant, give superior friction performance when compared to lubricants containing organic friction modifiers. The role of substrate material in tribofilm chemical and physical characteristics for all lubricants is discussed.
Donahue, R., Fabiyi, P. A. Manufacturing feasibility of all-aluminum automotive engines via application of high silicon aluminum alloy. SAE paper 2000-01-0061, 2000.
2.
BarnesA. M.BartleK. D.ThibonV. R. A.A review of zinc dialkyldithiophosphates (ZDDPs): characterisation and role in the lubricating oil. Tribol. Int., 2001, 24, 389–395.
3.
NichollsM. A.DaoT.NortonP. R.KasraiM.BancroftG. M.Review of the lubrication of metallic surfaces by zinc dialkyl-dithiophosphates. Tribol. Int., 2005, 38(1), 15–39.
4.
SpikesH.The history and mechanisms of ZDDP. Tribol. Lett., 2004, 17(3), 469–489.
5.
RudnickL.. Lubricant additives: chemistry and applications, 2003 (Marcel Dekker, New York).
6.
ATC. Lubricant additives and the environment. Document 49 (revision 1), 2007 (The Technical Committee of Petroleum Additive Manufacturers in Europe).
7.
MortierR.. Gasoline engine lubricants. Modern petroleum technology: downstreamLucasA. G.. vol. 2, 1999 (John Wiley & Sons, New York).
8.
PereiraG.LachenwitzerA.KasraiM.NortonP. R.CapehartT. W.PerryT. A.ChengY-T.FrazerB.GilbertP. U. P. A.A multi-technique characterisation of ZDDP antiwear films formed on Al (Si) alloy (A383) under various conditions. Tribol. Lett., 2007, 26(2), 103–117.
9.
NichollsM. A.NortonP. R.BancroftG. M.KasraiM.X-ray absorption spectroscopy of tribofilms produced from zinc dialkyl dithiophosphates on Al-Si alloys. Wear, 2004, 257, 311–328.
10.
FullerM.KasraiM.SheasbyJ. S.BancroftG. M.FyfeK.TanK. H.X-ray absorption spectroscopy of antiwear films on aluminum alloys generated from zinc dialkyldithiophosphate. Tribol. Lett., 1995, 1, 367–378.
11.
KawamuraM.FujitaK.Anti-wear property of lubricant additives for high silicon aluminium alloy under boundary lubricating conditions. Wear, 1983, 89, 99–105.
12.
NichollsM. A.NortonP. R.BancroftG. M.KasraiM.StasioG. D.WieseL. M.Spatially resolved nanoscale chemical and mechanical characterisation of ZDDP antiwear films on aluminum-silicon alloys under cylinder/bore wear conditions. Tribol. Lett., 2005, 18(3), 261–278.
13.
WanY.CaoL. L.XueQ. J.Friction and wear characteristics of ZDDP in the sliding of steel against aluminum alloy. Tribol. Int., 1997, 30(10), 767–772.
14.
XiaX.MorinaA.NevilleA.PriestM.RoshanR.WarrensC. P.PayneM.Tribological performance of an Al-Si alloy lubricated in the boundary regime with ZDDP and MoDTC additives. Proc. IMechE, Part J: J. Engineering Tribology, 2008, 222(3), 305–314.
15.
HuL.ChenJ.LiuW.XueQ.KajdasC.Investigation of tribochemical behavior of Al-Si alloy against itself lubricated by amines. Wear, 2000, 243, 60–67.
16.
LiuW.HuY.HeZ.ZhangP.XueQ.Friction and wear behaviour of an Al-Si alloy against steel lubricated with N- and O-containing organic compounds. Lubr. Sci., 1998, 11(1), 37–49.
17.
WanY.XueQ.LiuW.Tribological behaviour of lubricating oil additives in lubricated aluminum-on-steel contact. Wear, 1996, 196, 87–91.
18.
ChenC.BosseH.DetersL.Effects of various base oils and additives on the tribological behaviour of lubricated aluminiumon-aluminium and steel-on-aluminium contacts. Proc. IMechE, Part J: J. Engineering Tribology, 2009, 223(3), 571–580.
19.
PereiraG.LachenwitzerA.PaniaguaD. M.KasraiM.NortonP. R.CapehartT. W.PerryT. A.ChengY-T.Nanoscale chemistry and mechanical properties of tribofilms on an Al-Si alloy (A383): interaction of ZDDP, calcium detergent and a molybdenum friction modifier. Tribol. Mater. Surf. Interfaces, 2007, 1(1), 4–17.
20.
JimenezA. E.MorinaA.NevilleA.BermudezM. D.Surface interactions and tribochemistry in boundary lubrication of hypereutectic Al-Si alloys. Proc. IMechE, Part J: J. Engineering Tribology, 2008, 223(3), 593–601.
21.
WilliamsJ. A.. Engineering tribology, 1994 (Oxford University Press, Oxford).
22.
MorinaA.NevilleA.Understanding the composition and low friction tribofilm formation/removal in boundary lubrication. Tribol. Int., 2007, 40(10–12), 1696–1704.
23.
Fairley, N. CasaXPS Version 2.1.25.
24.
ASTM International standard E995-04. Standard guide for background subtraction techniques in Auger Electron Spectroscopy and X-ray Photoelectron Spectroscopy, 2004 (ASTM International, West Conshohocken, PA).
25.
ASTM International standard E996-04. Standard practice for reporting data in Auger Electron Spectroscopy and X-ray Photoelectron Spectroscopy, 2004 (ASTM International, West Conshohocken, PA).
Wagner, C. D., Naumkin, A. V., Kraut-Vass, A., Allison, J. W., Powell, C. J., Rumble Jr, J. R. NIST X-ray Photoelectron Spectroscopy Database. NIST Standard Reference Database 20, Version 3.4 (Web Version), 2003, available from http://srdata. nist.gov/xps/.
28.
MorinaA.NevilleA.PriestM.GreenJ. H.ZDDP and MoDTC interactions and their effect on tribological performance – tribofilm characteristics and its evolution. Tribol. Lett., 2006, 24(3), 243–256.
29.
MorinaA.NevilleA.PriestM.GreenJ. H.ZDDP and MoDTC interactions in boundary lubrication – the effect of Temperature and ZDDP/MoDTC ratio. Tribol. Int., 2006, 39, 1545–1557.
30.
BecS.TonckA.GeorgesJ. M.RoperG. W.Synergistic effects of MoDTC and ZDTP on frictional behaviour of tribofilms at the nanometer scale. Tribol. Lett., 2004, 17(4), 794–809.
31.
MuraseA.OhmoriT.ToF-SIMS analysis of model compounds of friction modifier adsorbed onto friction surfaces of ferrous materials. Surf. Interface Anal., 2001, 31, 191–199.
32.
PereiraG.LachenwitzerA.NichollsM. A.NortonP. R.StasioG. D.Chemical characterisation and nanomechanical properties of anti-wear films fabricated from ZDDP on a near hypereutectic Al-Si alloy. Tribol. Lett., 2005, 18, 411–427.
33.
GrahamJ.SpikesH.KorcekS.The friction reducing properties of molybdenum dialkyldithiocarbamate additives: part I – factors influencing friction reduction. Tribol. Trans., 2001, 44(4), 626–636.
