Wear metal analysis

MAINLUBE SUPERIOR MAINTENANCE LUBRICANTS PTY.
LTD.
14 Underwood Avenue, Botany NSW 2019, Sydney, Australia
Ph +61-2-9700-0880, Fax +61-2-9700-0881

Wear Particle Analysis
The Wear particle Analysis is a Pro-active Predictive
Maintenance System.
Wear Metals Particles are extracted from an oil sample
then magnified up to a 1000X for
wear mode identification.

Wear mode identification is possible when viewing;

> What the particles are,
> The particle’s size,
> How the metal particle was removed,
> Temperature of removal.

The above information can determine the machine’s
past, and therefore future Wear Mode.

Pro-Active Maintenance uses the Wear Mode
information to correct and prevent future reocurrence.

© Mainlube Superior Maintenance Lubricants Pty Ltd Page 1 of 17

Wear Modes in Machinery
Normal Rubbing Wear is when the machine’s normal operation lightly defoliates
the wear surface.
Normal Rubbing Wear Particles depending on the machine, are 0-10 microns
sized platelets. In a gearbox situation Normal Rubbing Wear could register
0-60 ppm of wear metals using Atomic Absorption Spectrometer.
This is a visual example of Normal Rubbing Wear Particles
@ 600X Sized 5-10 microns.

The images below are from machines that appear to be in an
“exaggerated” Normal Rubbing Wear Mode. If the wear mode is building,
then it’s not normal. (Scuffing Wear)
They are the end result of other larger wear modes being milled down as
they are forced through the load zone by the lubricant flow. They appear,
as a heavy concentration of Normal Rubbing Wear Particles.


Three Body Contact is the cause of most damage.

Below shows the normal “Lubricating Film Thickness” in each application in operating conditions.
Particles larger than the “lubrication film thickness” become Three Body Contact Contaminate Particles
as the lubricant flow forces them through the load zone, easily penetrating the lubricating film,
continually damaging load bearing surfaces
Roller Bearings 0.4 to 1 Micron
Ball Bearings 0.4 to 0.7 Micron
Journal Bearings 0.5 to 25 Microns
Hydrostatic Bearings 5 to 100 Microns
Gears 0.1 to 1 Micron
Dynamic Seal 0.05 to 0.5 Micron
Gear Pump, Tooth to side plate 0.5 to 5 Microns
Gear Pump, Tooth tip to case 0.5 to 5 Microns
Vane Pump, Sides 5 to 13 Microns
Vane Pump, tip 0.5 to 1 Micron
Piston Pump, piston to bore 5 to 40 Microns
Piston Pump, Valve plate to cylinder 0.5 to 5 Microns
Servo Valves, Orifice 130 to 450 Microns
Servo Valves, Flapper Wall 18 to 63 Microns
Servo Valves, Spool to Sleeve 1 to 4 Microns
Actuators 130 to 450 Microns
Human Hair 70 to 100 Microns


3 body Fatigue, Spheres, Laminar, Dark Metallo and Black Oxide
Wear Metal Particles are made possible by Fluid Contamination.

Abrasion Three-body sliding contact ploughs and cuts away material from component
surface, leading to loss of load bearing surface, misalignment and leakage.

Fatigue Three-body rolling contact roughens and microdents surfaces, fracturing
load bearing surfaces.

Erosion Particles suspended in high velocity fluid impact against surface, cutting
and wearing away load bearing surfaces.

Striction Particles lodged between machine components during the down periods cause
slip stick and jamming when machines restarted.

Fouling Of nozzles, flow passages, oil galleries, feed lines, heat exchangers.

Corrosion Attack by water or aggressive chemicals such as organic Acids formed
during oxidation of fluids.

Fluid Breakdown Involves diverse mechanisms such as contaminate catalysed reactions,
precipitation of additives by foreign chemicals or water, and depleting
anti-wear additives by particle induced wear.


Spherical Particles sized 4-5 microns are generated in 2 and 3 Body
Fatigue cracks on rolling bearing wear surfaces.
As the lubricant flow forces wear metals through rolling bearing tracks, 2 and 3
Body Fatigue cracks trap the wear metal debris, the rotation rolls the debris over
and, building the Sphere until it is large enough to escape. Research has shown,
as the bearing is failing, one to two million spheres will be released, pre-warning
an up and coming bearing failure. Other Spheres are generated in gears,
these Spheres are usually 10 microns or larger. The images below show
Spherical Wear Metal Particles from gears and bearings.


Sliding Wear occurs when the lubricants film strength has been insufficient in
providing separation between two wear surfaces, allowing metal to metal contact.
It’s like the glacier sliding down the hill, it bulldozers along the surface
tearing everything off in it’s path. Severe sliding wear generates extreme heat,
in some cases over 1000°C in the load zone. How many times you have seen
a large gearbox showing gear case temperatures above 100°C?
How much energy would it take to heat the gearbox to this temperature?
How much energy is being wasted by tearing off metal, which could be
turned into production?
To generate this heat, the machine is tearing off of 50 to 200 micron
chunks of metal and releasing them into the lubricant flow. This forces
the metal chunks through the rolling elements of the machine causing
secondary wear. Gear faces subject to high temperatures over time,
anneal the gear tooth surfaces, softening them promoting further wear.
Here are examples of Sliding Wear Particles 500X-600X Sized 40-200 Microns.


Cutting Wear Particles are caused by hard contamination, usually
Silica (Sand), or other hard contaminants, or an acute angle of
metal to metal contact that has occurred between the machine’s components.
The distinctive curled swarf, shapes of Cutting Wear Particles, show a hard
contaminate has penetrated the lubricating film, gouging out the metal.
Cutting Wear is an abnormal wear mode. Cutting Wear Particles results
in machinery damage and should corrected as soon as possible.
Filtergram Analysis identifies all wear mode types present, then recommends
changes and monitors the immediate effect of the changes to ensure success.


2 Body Fatigue Wear chunks occur when the machines cyclic application
of the stress, is in excess of the design value.
The machine has been overloaded, past the capabilities of the metals surface,
slightly collapsing the metals sub-surface creating a crack or dent.
Repetitive bruising in this area further fractures the metals sub-surface causing
the area to eventually spall out. This creates the familiar deep pitting and scaring
damage observed on load bearing surfaces. Spheres are usually generated in
these areas.
2 Body Fatigue Wear Particles are flat platelets with a major dimension to
thickness ratio of approximately 10:1, a smooth surface and a random
irregularly shaped circumference.
These spalling metal particles are carried by the oil flow through other load
zones, snowballing the effect and further damaging load-bearing surfaces.
Damage will continue to this machine until the contamination is completely
removed


3 Body Fatigue Wear Chunks are wear metal Particles that began when
a foreign body was forced through the load zone creating a micro crack or dent.
Repetitive bruising in this area fractures the metals surface, causing the area to
eventually spall out. This creates the familiar loss of hardened surface, scaring
and light pitting damage observed on load bearing surfaces.
These spalling metal particles are carried by the oil flow through other load
zones, snowballing the effect and further damaging load-bearing surfaces.
removed.
changes and monitors the immediate effect of the changes to ensure success. If
not corrected this wear mode will escalate in Scuffing Wear and eventual failure.
Three Body Wear

Scuffing Wear

© Mainlube Superior Maintenance Lubricants Page 9 of 17

Scuffing Wear Typical of “Running In” mode.
New machinery must be “run in” to allow load-carrying surfaces to “bed in”.
When the components of a machine are new, especially after an overhaul,
bearings and gears can be sourced from may different places. There are hills
and valleys present that must be smoothed out to achieve the correct “light
defoliation” of the wear surface to settle the machine down into Normal Rubbing
Wear mode.
After a machine has “bedded in” the machine must be flushed and refilled with
fresh lubricant. If left, scuffing wear will be carried by the oil flow through other
load zones, snowballing the effect generating 3 Body Fatigue Wear, then on to
Laminar Wear and further damaging the new load bearing surfaces.
removed.
Filtergram Analysis identifies all wear mode types present then recommends
The images below are from a large reduction box that has been freshly
overhauled and run for 100 hours and benchmarked.


Red Iron Oxide Particles are easily formed when water is present in the
system, or has been in the system in the past.
If heavy amounts of large Red Iron Oxide Particles are found in the sample, this
will indicate the presents of water in the system.
Red Iron Oxide particles vary in colour and size with the amount of water present.
The presence of other minerals, in the water and the size of the crystals, all have
an effect on the way the Red Oxide Particles form. Below are several different
forms of Red Iron Oxide Particles, the effect of the formation of these particles
on the metal surfaces causes severe surface corrosion damage and subsequent
loss of load carrying surface area, this is catalysed by the formation of the Red
Iron Oxide Particles.


Dark Metallo & Black Oxide Particles are formed when machine is being over
driven beyond the capability of the lubricant. The heat and pressure generated
causes lubricant starvation. When Red Iron Oxide (rust), is forced through the
load zone it polymerises and forms Dark Metallo-Oxide and Black Oxide
Particles. Water is not present when Black Oxide Particles and Dark Metallo-
Oxides are formed. There are many forms of Iron Oxides FeO, Fe2O3 and
Fe3O4.
To rectify this wear mode the lubricant should be up graded to a product more
suitable to the machines operating environment. It is not unusual to see particles
oxidised to varying degrees of colour , from straw through to blue purple.


Laminar Wear is a secondary wear mode, which is the end result of all wear
modes being forced through the load zone by the lubricant flow. Their passage
damages load bearing surfaces, forming large “rolled out” particles that contain
all wear modes created earlier. The machine’s rolling elements roll the abnormal
Wear Metal Particles flat, to the distinctive length to thickness 30:1 ratio.
Typical operating lubrication film clearance in Industrial Ball Bearing, Roller
Bearing and Meshing Gear Sets are of 0.1 to 1-Micron clearance. When spalls or
breakages occur, or foreign contaminates are introduced to the lubrication
system, the foreign particles could be 100’s of microns in size, the human hair is
60 to 100 microns in diameter. The lubricant flow forces these huge foreign
particles, through the machine’s rolling gears and bearings causing extensive
damage to the machines running surfaces.
As these chunks of metal, up to 500 microns in size, are forced through the
bearings and gears, with a maximum clearance of 1 micron, they crush and mill
down forming the 0 to 15 microns sized abnormal wear metals that register when
an Atomic Absorption Spectrometer test is preformed. Most people have
trended the wear rate using the Atomic Absorption Spectrometer from the
local Caterpillar Agent or Fuel Company. The problem with this type of
analysis is wear particles are required to be milled down by the
machine’s rolling elements to the small size of 0-10 microns before they
register in the test. Particles bigger than 10-micron increase the particle
count but cannot be identified. This means this the Atomic Absorption
Spectrometer often only registers the introduction of a contaminant 2 to 3
months after the event. Undetected contaminates cause extensive damage to
the machine’s wear surfaces, shortening their life by cracking and denting the
surface in the end forming other abnormal wear metals shown ahead. Filtergram
Analysis identifies all wear mode types present, then recommends changes and
monitors the immediate effect of the changes to ensure success.
Damage will continue to the machine until the contamination is completely
removed.

Here are examples of Laminar Wear Particles 500X-600X Sized 40-200

Microns.

Note: See how as the time extends the particles are broken up smaller.


ISO SOLID CONTAMINANT CODE ISO 4406

Range Number Chart

Range Number 24 indicates 80,000 to 160,000 particles per ml of oil







Range Number 17 indicates 640 to1,300 particles per ml of oil

Range Number 16 indicates 320 to 640 particles per ml of oil







Range Number 9 indicates 2.5 to 5 particles per ml of oil

Range Number 8 indicates 1.3 to 2.5 particles per ml of oil








© Mainlube Superior Maintenance Lubricants Pty Ltd Page 15of 17

ISO SOLID CONTAMINANT CODE ISO 4406

The ISO Solid Contaminant Code ISO 4406 is the single most wide spread system for representing contaminant
levels in Hydraulic or Lube Oil Systems.
ISO 4406 uses 2 range numbers, the first one representing particle counts above 5 microns and the second one
represent particles counts above 15 microns.
The first range number is separated for the second range number by a slash, (eg 15/12) From the chart, the particle
count ranges correspond to each adjacent range.
A typical ISO Code for a hydraulic system is ISO 16/13.
By checking the Range Chart we can see that
Range Number 16 means there are between 320 and 640 particles per ml of oil bigger than 5 microns.
And
Range Number 13 means there are between 40 and 80 particles per ml of oil bigger than 15 microns included in this
first total of between 320 and 640 particles per ml of oil.
This equates to approximately I milligram of dirt per litre of fluid or 1 ppm.

A Vickers Chart of Recommended Cleanliness Codes uses the Pal or Vickers System, same as this ISO 4406
System’s Range Numbers. Vickers being a leading Hydraulic Equipment Manufacturer developed this system to
prevent unnecessary wear in hydraulic systems.
The difference between the Vickers System and ISO 4406 is that Vickers also consider particles 2 microns and
greater, this range is recorded by adding another set of numbers in front for the number of particles greater than 2
microns. eg 18/15/12, or;
(1300 to 2500 particles >2 microns/ 160 to 320 particles >5 microns/ 20 to 40 particles >15 microns).
At all times the first Range Number will indicate the total number of particles of all sizes per ml of lubricant, the
subsequent Range Numbers indicate the sizing of the particles in this first total
Both systems without the previous page’s chart offer limited information until the system has been learnt and
understood. Once this is accomplished the user will notice any unusual Range Number changes and be very accurate
with early detection and correction of abnormal wear modes.


Mainlube Lubricant’s Analysis Requesting Sheet
Test No.
Maintenance Lubricants Pty Ltd, PO Box 353, Botany NSW 1455
14 Underwood Avenue, Botany NSW 2019 Ph.02-9700-0880, Fax 9700-0881, E-mail: info@mainlube.com.au

Today’s Date: ___/___/___ Sample Received: ___/___/___Lab Sent: ___/___/___ Test Results: ___/___/___
NOTE: TO ENSURE PROCESSING OF THIS SAMPLE ALL APPLICATION DETAILS MUST BE COMPLETED
CUSTOMER NAME, ADDRESS, PH & FAX.

_________________________________________________________________________________________________

_________________________________________________________________________________________________

_________________________________________________________________________________________________

Attention : Phone : Fax :

NOTE: TO ENSURE PROCESSING OF THIS SAMPLE ALL APPLICATION DETAILS MUST BE COMPLETED
APPLICATION DETAILS
Unit, Vehicle, Plant, Rego,
Id, Number, Name, etc:______________________________________ Equipment Make :_________________________

Equipm ent Model:____________________ Total Machine Hours/Kms:_____________ Hours/Kms on Oil:______________
Lubricant Brand,
Machine Location :___________________________ Type, & SAE :___________________________________________
Filter Changed: Yes / No. Fuel Type: Diesel/Petrol/Electric/Gas Other ___________________

Top Up Ltrs : ______________. Oil Changed: Yes / No. OIL QUANTITY _________Litres HP/kW _______________
Sample Taken From:
θ Engine; θ Hydraulics; θ Reduction Gearbox; Type:_____________ θ Manual Transmission; θ Auto Transmission;
θ Front Axle; θ Rear Axle; θ Final Drive which? __________;θ Turbine; θ Bearing Housing & Type__________________
θ Air Compressor; θ Refrigeration Compressor; θ Vacuum Pump; θ Heat Transfer System;
Other ___________________

Metal Types expected in sample
eg: Steel, Bronze etc:___________________________________________________________________________;
How & Where Was
Sample Taken: ___________________________________________________________________________________

Any Recent repairsrepairs:___________________________________________________________________________

_________________________________________________________________________________________________
Please continue on back of form with further relevant observations on, Lubricant smell, visual appearance,
type of environment, temperature etc, Information Important to Oil Test:
θ θ

Person Completing/Requesting Test,

Print Name: ___________________________Signed: ________________________Date: ____/____/____

TEST TYPES REQUIRED:
Wear Particle Analysis @ $85 per each normal to $140 on complex samples. Predicts future wear & machine life, checks
machine’s condition often providing several months warning of component failure allowing planned downtime.

Wear Metal PPM Analysis @ $70 Per Sample. Used for evaluating past machine wear, provides PPM Wear Metals
Sized 0-5 Microns, Particle Count, Water, Fuel, Soot, Oxidation.

Lubricant Condition Analysis @ $70 Per Sample. Used for establishing lubricant condition, whether
lubricant should be changed and project remaining lubricant life.
Please Note: Urgent Rush Wear Particle Analysis can be completed @ plus 100% rate, turn around approx 2 hours from
receipt.

Please do not completely fill the sample bottle as this can prevent correct agitation and subsequent testing. Please fill the
Mainlube sample bottle to between the 2 nd and 3rd rings, about ¾ full. For Wear Metal PPM Analysis also fill the Red Cap with
the same unused clean new oil as the sample. Affix the white Cap and fill out this sheet correctly and send with sample to
the above address. Photocopy this sheet and fill out to send with your sample and keep for your records.

Wear metal analysis

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