Standard Test for Wear Rate and Coefficient of Friction of Materials in Self-Lubricating Rubbing Contact with a Thrust Washer Using the Micro-Tribometer mod. UMT -2

ASTM D3702-94 (Reapproved 1999)

Summary of Test Method:

This test method involves a rotating test specimen pressed against a stationary steel washer under a prescribed set of conditions. The test specimen is disk shaped with a raised outer rim, which is the wear surface. The inside diameter of the rim is 25.5 mm, the outer diameter is 28.55 mm. Each test has a break-in period of 40 hours, followed by a selected test duration at the same load and speed (see table below). Wear rate and coefficient of friction are calculated based on periodic thickness measurements of the test specimen and in-situ torque measurements.

The UMT applies a programmable load downward by a servo driven carriage. The test can be performed with either Configuration A: the upper test specimen is rotated against a stationary washer as described in the standard, or Configuration B: the upper test specimen is stationary and the washer is rotated. The actual dynamic normal load, friction torque and coefficient, and depth of wear are monitored during the test.  Optionally, additional parameters of contact acoustic emission and temperature are measured.

Test Conditions

UMT Hardware Configuration A:

·         Upper Rotational Motion Drive mod. USMHH

·         Model TH 6-axis Torque/Force Sensor

-          Torque Range: 5 to 1000 N*mm

-          Load Range: 0.05 to 5 kg

·         Suspension with Linear Guide-AM30C110F-1

·         Test Specimen Holder

·         Test Specimen

·         Washer

·         Washer Holder

·         Stationary Table

·         Optional Additional Sensors

 - mod AE-5 Acoustic Emissions Sensor

 - mod. TMR-150 Temperature Measurement & Recording

-    mod. RTD Temperature Sensor

UMT Software Test Setup for Configuration A:

UMT Options File:

Load the options file that contains settings for the Upper Rotational Motion Drive and the 5 kg torque/force sensor.

Use the Semi-Automatic Mode to pre-position the x-axis slider so that the test specimen is concentric with the washer.

Test Sequence:

The Test Sequence should consist of 3 sheets.

Sheet 1 is for settling time for the carriage to establish the initial normal load.

     Carriage - applies a 1.1 kg Constant Force for a Duration of 10 sec.

     Spindle 1  – Velocity is 0 revs/min.

     Spindle 2  – Velocity is 0 revs/min.

     Slider     – is idle.

Sheet 2 is a 40 hour break-in period

     Carriage - applies a 1.1 kg Constant Force for a Duration of  40 hours.

     Spindle 1  – Velocity is 0 revs/min.

     Spindle 2  – Velocity is 180 revs/min, Move-Continuous,  and Direction- Clockwise

     Slider      – is idle.

Sheet 3 is a 100 hour test period

     Carriage - applies a 1.1 kg Constant Force for a Duration of  100 hours.

     Spindle 1  – Velocity is 0 revs/min.

     Spindle 2 – Velocity is 180 revs/min, Move-Continuous,  and Direction- Clockwise

     Slider      – is idle.

Data Collection:

The following should be checked under DataFile:

    Tz – Torque

    T   – Time

    Z1 – Carriage Position (Used to determine Wear Depth)

    Te - input – Temperature (optional)

    AE – Acoustic Emission (optional)

    EC – Electrical Contact Resistance

UMT Hardware Configuration B:

·         4” Mounting Block – PN M30C116

·         Model TH 6-axis Torque/Force Sensor

-          Torque Range: 5 to 1000 N*mm

-          Load Range: 0.05 to 5 kg

·         Suspension with Linear Guide-AM30C110F-1

·         Test Specimen Holder

·         Test Specimen

·         Washer

·         Washer Holder

·         Medium Torque Rotation Drive

-    Mod. SHHM

·         Optional Additional Sensors

 - mod AE-5 Acoustic Emissions Sensor

 - mod. TMR-150 Temperature Measurement & Recording

-    mod. RTD Temperature Sensor

UMT Software Test Setup for Configuration B:

UMT Options File:

Load the options file that contains settings for the Medium Torque Rotational Motion Drive and the 5 kg torque/force sensor.

Use the Semi-Automatic Mode to pre-position the x-axis slider so that the test specimen is concentric with the axis of the  rotational drive.

Test Sequence:

The Test Sequence should consist of 3 sheets.

Sheet 1 is for settling time for the carriage to establish the initial normal load.

     Carriage - applies a 1.1 kg Constant Force for a Duration of 10 sec.

     Spindle  – Velocity is 0 revs/min.

     Slider     – is idle.

Sheet 2 is a 40 hour break-in period

     Carriage - applies a 1.1 kg Constant Force for a Duration of  40 hours.

     Spindle   – Velocity is 180 revs/min, Move-Continuous,  and Direction- Clockwise

     Slider      – is idle.

Sheet 3 is a 100 hour test period

     Carriage - applies a 1.1 kg Constant Force for a Duration of  100 hours.

     Spindle   – Velocity is 180 revs/min, Move-Continuous,  and Direction- Clockwise

     Slider      – is idle.

Data Collection:

The following should be checked under DataFile:

    Tz – Torque

    T   – Time

    Z1 – Carriage Position (Used to determine Wear Depth)

    Te - input – Temperature (optional)

    AE – Acoustic Emission (optional)

    EC – Electrical Contact Resistance

Report:

Use the Viewer program to plot test results.

Select the parameters to be displayed by checking

the appropriate boxes under Parameters on the Viewer screen.