Analysis of Wear Metals in Lubricating Oil ICP-OES & ASTM Methodology

Advanced Research Center106 Access Rd, Suite 3

Norwood, MA 02602781-762-2766

Slide info courtesy of

SPECTRO Analytical Instruments 91 McKee DrMahwah NJ 07430

2

Main petrochemical applications

Blending control of fresh lubricants, greases and control of the additive packages

Used oil analysis

Analysis of sulfur content in crude oil distillates

Analysis of sulfur and trace element content in crude oil and residual heavy fuel

Analysis of trace element content in diesel/biodiesel fuel

3

What is a lubricating oil

Lubricating oils are formulated with a number of chemicals blended into base oils to provide products that

last longer keep machinery cleaner allow the machinery to work better under severe operating conditions

These organic chemicals, better known as additives, contain organometallic and inorganic compounds as their active ingredients

Lubricating oils contain: – 70 - 99 % base oil– 1 - 20 % additive package– 0 - 15 % viscosity index improvers

(macromolecular compounds with a molecular weight between 25 000 -100 000)

4

Additive packages

Elemental range:

B: up to 6 % Mg: up to 9 % Si: up to 13 % P: up to 11 % S: up to 45 % Cl: up to 35 % Ca: up to 17 % K: up to 8 % Zn: up to 12 % Mo: up to 8.5 %

ADDITIVE TYPICAL COMPOUNDS TYPICAL ELEMENTS

Detergents Metal Sulfonates Metal Phenates

Na, Mg, Ca, K, Ba

Antioxidants and Antiwear Agents

Metal Dithiophosphates Metal Dithiocarbamates

P, S, Cu, Zn, Mo

Extreme Pressure and Lubricity Agents

Metal Naphtenates Molybdenum Disulfide Powdered Metals Graphite Chlorinated Olefins

P, S, Cl, Cu, Zn, Mo, P

Antifoamants Silicones Si

Thickeners Soaps Li, Na, Al, Ca

5

Type of lubricating oils

Engine oils– Ca between 1000 - 2500 ppm– Zn/P between 600 - 2300 ppm– Mo between 0 - 400 ppm – Mg between 0 -1200 ppm

Marine oils– Ca between 2500 - 28000 ppm– Zn/P between 0 - 700 ppm

Industrial oils– All additives lower than 500 ppm

Transmission oils– Variable

6

Used oil analysis

Determination of additive element content– information pertaining to additive depletion in service and possible

charging of the system with the wrong oil

– ICP-OES analysis according to ASTM D4951 (9 elements)

Determination of wear element content– information pertaining to increased wear rate and possible abnormal

operating conditions

– ICP-OES analysis according to ASTM D5185 (22 elements)

7

Wear elements: spectroscopic operating baseline

For interpretation of the results trend analysis is more important than an individual reading

8

Condition monitoring elements and their significance

Wear Metals Contaminants

Fe Many sources, the element most frequent Si Airborne dust, seals, coolant, additive

Cr B Coolant contaminant, additive

Pb Bearings, bushings, solders K Coolant, contaminant

Cu Bearings, bushings, additive Additives

Sn Bearings, piston rings, solders Ca Contaminant from dust, additive

Sb P

Al Pistons, bearings Zn Brass components, additive

Ni Bearings, turbine blades Mo Piston rings, coolant contamination, additive

Ag Bearings, silver solders Si Airborne dust, seals, coolant, additive

Mo Piston rings, coolant contamination, additive B Coolant contamination, additive

Zn Brass components, additive Mg

Ti Turbine blades (aircraft engines) Ba

V

9

Elemental scope for fresh and used lubricants

Scope ICP-OES B, Na, Mg, Si, P, S, Cl, K, Ca, V, Cr, Mn, Fe, Ni, Cu, Zn,

Mo, Cd, Sn, Sb, Ba, Pb

Scope XRF B, Na, Mg, Si, P, S, Cl, K, Ca, V, Cr, Mn, Fe, Ni, Cu, Zn,

Mo, Cd, Sn, Sb, Ba, Pb Note: B, Na, and Mg are not as analytically accurate by XRF!

10

PARTICLE COUNTING:

Relation between particle size and percentage of recover

Please visit our website for additional info!

www.advresearchctr.com