Standard Test Method for Measuring Friction and Wear Properties of
Extreme Pressure (EP) Lubricating Oils using the Micro-Tribometer mod.
UMT-2
ASTM D6425-99
Summary of Test Method:
This
test method utilizes a horizontally mounted flat disc covered with the
lubricant specimen, and a ball that slides against the disc in a linear, back
and forth motion. The disc is held at a constant temperature. The load is
applied downward onto the ball. The coefficient of friction is recorded during
the test, and the wear scar diameter is measured at the end of the test.
The
load, stroke length, frequency of oscillation, test temperature, test duration,
ball and disc material and dimensions can be varied from those specified in the
table below.
Test Parameters
|
Qty. Lube |
Temperature |
Applied Load |
Stroke Length |
Osc.
Frequency |
Duration |
|
0.03 mL |
50ºC |
300 N |
1.0 mm |
50.0 Hz |
2 h |
Test Ball: AISI 52100 Steel , 10 mm dia., 60 HRC
Test Disc: AISI 52100 Steel , 24 mm dia., 62 HRC
The
UMT allows for monitoring during the test the actual dynamic normal load,
friction force and friction coefficient, temperature, and depth of wear.
Optionally, it can measure additional parameters of contact acoustic emission
and electrical contact resistance.
UMT
Hardware Configuration:
·
4”
Mounting Block – PN M30C116
·
Model
DFH-50 Dual Friction/Load Sensor
-
range
5.0 N to 500 N
·
Suspension
with Linear Guide-AM30C110D-1
·
10
mm Ball Holder –AM30B310B
- for sensors mod.
DFH
·
10
mm Diameter Test Ball – PN BM110006
·
SS
Test Disc - PN M30B244
·
Elevated
Temperature Chamber for Reciprocating Drive
·
Lower
linear
Manually adjust for 1 mm
travel.
- mod. RHH
·
Optional
Additional Sensors
- mod.
ECR-xx Electrical Contact Resistance
- mod. AE-5 Contact
Acoustic Emission Detector
- mod.
TMR-150 Temperature Measurement & Recording
- mod.
RTD Temperature Sensor
UMT Software Test
Setup:
UMT Options File:
Load the options file that contains settings for
the Linear Reciprocating Motion drive and the 500N force/load sensor.
Test Sequence:
The Test Sequence should consist of 2 sheets.
Sheet 1 is for settling time for the normal load
and temperature.
Carriage - applies a 300 N Constant Force for a Duration of 10 sec.
Spindle – Velocity is 0 revs/min.
Slider
– is idle.
Sheet 2 is for the actual test.
Carriage - applies a 300 N Constant Force for a Duration of 2 hours.
Spindle
– Velocity is 3000 revs/min, Move-Continuous, and Direction-
Clockwise
Slider
–
is idle.
Data Collection:
The following should be checked under DataFile:
Fx – Friction Force
Fz –
Normal Force
T – Time
Z1 –
Carriage Position (Used to determine Wear Depth)
Te – Temperature
EC – Electrical Contact
Resistance (optional)
AE – Contact Acoustic Emissions (optional)
Report:
Use the Viewer program to plot test results.
Select the parameters to be displayed by checking the appropriate box under Parameters on the Viewer screen.
For viewing COF plots of reciprocating tests check the Fz box, click on the Symmetry button, click on the Peak Detect button, and then check the COF box.
