Tribology and Mechanical Testing Unit

Transcription

1 Pin Abrasion Testing Using the Micro-Tribometer mod. CETR-UMT 2 ASTM G Test method for determining the wear resistance of a pin of test material during sliding on an abrasive cloth, paper, or plastic film using the UMT in a pin-on-disk configuration, pin-on-drum configuration, and Pin-on-flat (x-y) configuration Summary of Test Method: In this test method the pin upper specimen is perpendicular to and sliding against the abrasive surface of a lower specimen which is mounted on either a flat circular disk, or a cylindrical of a drum, or a flat lateral positioning table. The wear track of the pin is a continuous, non-overlapping path such as a spiral, a helix, or a square wave. The UMT applies the load vertically downward with a motor driven carriage that uses a force/load sensor for feedback to maintain a constant load. The UMT allows for monitoring during the test the actual dynamic normal load, friction force and friction coefficient, and depth of wear. Optionally, it can measure additional parameters of contact acoustic emission and temperature. ASTM G does not specify test parameters such as rpm, load, or test duration, but lists typical parameters Pin Diameter Load Translational Speed Pin Rotation Track Length 6.3 mm 67 N 0.04 m/sec. None or 17 to 20 rpm 4 to 16m Typical Test Results The Viewer software program is used to plot test results. The recorded parameters are displayed by checking the appropriate boxes such WR for wear and COF for coefficient of friction under Parameters on the Viewer screen. Described on the following pages are six possible UMT configurations for performing this test: Non-rotating Pin on Rotating Disk Rotating Pin on Rotating Disk Non-rotating Pin on Rotating Drum Rotating Pin on Rotating Disk Non-rotating Pin on Flat Rotating Pin on Flat The configurations used in these examples are just a few of the many possible combinations of friction/load sensor, rotational drive, specimen holder, and specimens.

2 Non-Rotating Pin-on-Disk Test Method: This test method uses a lower rotational drive with a 6 diameter specimen table on which an abrasive disk is fastened. While the lower drive rotates, the pin is slid across the abrasive disk with the x-axis stage. The wear track of the pin is a continuous, nonoverlapping spiral path. The UMT automatically varies the rpm of the lower specimen and the velocity of the x-axis stage to maintain a constant translational speed between the pin and the disk. UMT Hardware Configuration for Non-Rotating Pin-on-Disk: 4 Mounting Block PN M30C116 Model DFH-10 Dual Friction/Load Sensor - range 1 N to 100 N Lapping Disk, Dia. 6, 3.0 micron Alumina particles Medium Torque Rotation Drive - Mod. SHHME Adapter Table, Dia. 6 - PN M30D089B UMT Software Test Setup for Non-Rotating Pin-on-Disk: Load the options file that contains settings for the Medium Torque Rotational Motion Drive and the 100 N force/load sensor. Use the Semi-Automatic Mode to pre-position the x-axis stage so that the pin is 5 mm from the center of rotation of the lower specimen. This will be the start of a non-overlapping spiral wear track with a length of 3 meters. The track radius expands by 6.35mm per revolution. The translational velocity is constant at 40 mm/sec. Spindle Velocity is 0 revs/min. Carriage - applies a -67 N Constant Force for a Duration of 75 seconds. Spindle Velocity is 2400 mm /min, Move-Continuous, and Direction- Clockwise Stage Working Velocity is 6.35 mm/rev. spindle 1, Initial Positioning Velocity is 2 mm/sec., and Position is Absolute from 5 mm to 75 mm. Check Move Immediately. Page 2

3 Rotating Pin-on-Disk Test Method: This test method uses a lower rotational drive with a 6 diameter specimen table on which an abrasive disk is fastened. The pin is attached to the upper rotational drive. While the upper and lower drives rotate, the pin is slid across the abrasive disk with the x-axis stage. The wear track of the pin is a continuous, non-overlapping spiral path. The UMT automatically varies the rpm of the lower specimen and the velocity of the x-axis stage to maintain a constant translational speed between the pin and the disk. The upper rotational drive spins at a constant rpm. Because the pin is rotating, its wear is typically greater than that in the previous non-rotating pin test. UMT Hardware Configuration for Rotating Pin-on-Disk: Model USMHH Upper Rotational Drive Model DFH-10 Dual Friction/Load Sensor (internal to Upper Rotational Drive) range 1 N to 100 N Lapping Disk, Dia. 6, 3.0 micron Alumina particles Medium Torque Rotation Drive - Mod. SHHME Adapter Table, Dia. 6 - PN M30D089B UMT Software Test Setup for Rotating Pin-on-Disk: Load the options file that contains settings for the Medium Torque Rotational Motion Drive for spindle 1, and the Upper Rotational Drive with internal 100 N force/load sensor for spindle 2. Use the Semi-Automatic Mode to pre-position the x-axis stage so that the pin is 5 mm from the center of rotation of the lower specimen. This will be the start of a non-overlapping spiral wear track with a length of 3 m. The track radius expands by 6.35mm per revolution. The translational velocity is constant at 40 mm/s. Spindle1 Velocity is 0 revs/min. Spindle2 Velocity is 0 revs/min. Carriage - applies a -67 N Constant Force for a Duration of 75 seconds. Spindle1 Velocity is 2400 mm /min, Move-Continuous, and Direction- Clockwise Spindle2 Velocity is 20 rev /min, Move-Continuous, and Direction- Clockwise Stage Working Velocity is 6.35 mm/rev. spindle 1, Initial Positioning Velocity is 2 mm/sec., and Position is Absolute from 5 mm to 75 mm. Check Move Immediately. Page 3

4 Non-Rotating Pin-on-Drum Test Method: This test method involves a pin upper specimen that slides against an abrasive surface of a drum mounted on a lower block-on-ring drive. While the lower drive rotates, the pin is slid across the abrasive surface with the x-axis stage. The rpm of the lower drive and velocity of the upper specimen are constant. The wear track of the pin is a continuous, non-overlapping helix. UMT Hardware Configuration for Non-Rotating Pin-on-Drum: 4 Mounting Block PN M30C116 Model DFH-10 Dual Friction/Load Sensor - range 1 N to 100 N Drum, Dia. 110mm, Length 80mm Block-on-Ring Drive - Mod. BHHM UMT Software Test Setup for Non-Rotating Pin-on-Drum: Load the options file that contains settings for the Block-on-Ring Drive and the 100 N force/load sensor. Use the Semi-Automatic Mode to pre-position the x-axis stage so that the pin is 5 mm from the right hand edge of the drum. This will be the start of a nonoverlapping wear track with a length of 4 m. The x-stage moves to the left by 6.5mm per revolution of the drum. The translational velocity is constant at 40 mm/s. Spindle Velocity is 0 revs/min. Carriage - applies a -67 N Constant Force for a Duration of 100 seconds. Spindle Velocity is 6.95 rev. /min, Move-Continuous, and Direction- Clockwise Stage Working Velocity is.75 mm/sec., Initial Positioning Velocity is 2 mm/sec., and Position is Increment Offset 75 mm., Check Move Immediately, Direction Left. Page 4

5 Rotating Pin-on-Drum Test Method: This test method involves a rotating pin upper specimen that slides against an abrasive surface of a drum mounted on a lower block-onring drive. The pin is attached to the upper rotational drive. While the upper and lower drives rotate, the pin is slid across the abrasive drum with the x-axis stage. The rpm of the upper and lower drives and the velocity of the x-axis stage are constant. The wear track of the pin is a continuous, non-overlapping helix. Because the pin is rotating, its wear is typically greater than that in the previous non-rotating pin test. UMT Hardware Configuration for Rotating Pin-on-Drum: Model USMHH Upper Rotational Drive Model DFH-10 Dual Friction/Load Sensor (internal to Upper Rotational Drive) - range 1 N to 100 N Drum, Dia. 110mm, Length 80mm Block-on-Ring Drive - Mod. BHHM UMT Software Test Setup for Rotating Pin-on-Drum: Load the options file that contains settings for the Block-on-Ring Drive for spindle 1, and the Upper Rotational Drive with internal 100 N force/load sensor for spindle 2. Use the Semi-Automatic Mode to pre-position the x-axis stage so that the pin is 5 mm from the right hand edge of the drum. This will be the start of a non-overlapping wear track with a length of 4 m. The x-stage moves to the left by 6.5mm per revolution of the drum. The translational velocity is constant at 40 mm/s. Spindle1 Velocity is 0 revs/min. Spindle2 Velocity is 0 revs/min. Carriage - applies a -67 N Constant Force for a Duration of 100 seconds. Spindle1 Velocity is 6.95 rev. /min, Move-Continuous, and Direction- Clockwise Stage Working Velocity is.75 mm/sec., Initial Positioning Velocity is 2 mm/sec., and Position is Increment Offset 75 mm., Check Move Immediately, Direction Left. Page 5

6 Non-Rotating Pin-on-Flat Test Method: This test method involves a pin upper specimen that slides against an abrasive surface on a lower y-axis stage. While the lower stage is stationary, the pin is slid across the abrasive surface with the x-axis stage. At the end of each x-axis stroke the y-axis stage moves the width of the pin toward the rear. The x-axis stage reverses direction, and the sequence is repeated until the entire abrasive surface has been covered. The wear track of the pin is continuous and nonoverlapping. The maximum travel of the x and y-axis stages is 75mm, which corresponds to a coverage area of 5625 mm². For non-overlapping tracks with a width of 6.35 mm, the maximum length of the wear track is thus 807 mm (10 tracks X 75mm in the x direction plus 9 tracks X 6.35mm in the y direction). The maximum velocity of the x and y-axis stages is 10 mm/sec. UMT Hardware Configuration for Non-Rotating Pin-on-Flat: 4 Mounting Block PN M30C116 Model DFH-10 Dual Friction/Load Sensorrange 1 N to 100 N - For sensors mod. DFH Abrasive Sheet with Adhesive Backing Lateral Positioning and Sliding Drive - Mod. LWY-M UMT Software Test Setup for Non-Rotating Pin-on-Flat: Load the options file that contains settings for the Lateral Positioning and Sliding Drive and the 100 N force/load sensor. Use the Semi-Automatic Mode to pre-position the x-axis stage so that the pin is 5 mm from the right hand edge of the abrasive sheet. Pre-position the y-axis stage so that the pin is 5 mm from the back edge of the abrasive sheet. This will be the start of a non-overlapping wear track with a length of m. Test Sequence: The Test Sequence should consist of 20 sheets. Spindle Velocity is 0 revs/min. Sheet 2 moves the pin from right to left 75mm. Spindle Velocity is 0 rev. /min, Move-Continuous, and Direction- Clockwise Stage Working Velocity is 10 mm/sec., Initial Positioning Velocity is 2 mm/sec., and Position is Increment Offset 75 mm., Check Move Immediately, Direction Left. Sheet 3 moves the pin from back to front 6.35mm. Spindle Velocity is 600 rev. /min, Move-Increment, Distance 6.35 rev. and Direction- Clockwise Sheet 4 moves the pin from left to right 75mm. Spindle Velocity is 0 rev. /min, Move-Continuous, and Direction- Clockwise Stage Working Velocity is 10 mm/sec., Initial Positioning Velocity is 2 mm/sec., and Position is Increment Offset 75 mm., Check Move Immediately, Direction right. Sheet 5 moves the pin from back to front 6.35mm. Spindle Velocity is 600 rev. /min, Move-Increment, Distance 6.35 rev. and Direction- Clockwise Repeat sheets 2 through 5 three more times, and then sheets 2 through 4 one time by doing copy and paste for a total of 20 sheets. Page 6

7 Rotating Pin-on-Flat Test Method: This test method involves a rotating pin upper specimen that slides against an abrasive surface on a lower y-axis stage. While the lower stage is stationary, the pin is slid across the abrasive surface with the x-axis stage. At the end of each x-axis stroke the y-axis stage moves the width of the pin toward the rear. The x-axis stage reverses direction, and the sequence is repeated until the entire abrasive surface has been covered. The wear track of the pin is continuous and non-overlapping. The maximum travel of the x and y-axis stages is 75mm, which corresponds to a coverage area of 5625 mm². For non-overlapping tracks with a width of 6.35 mm, the maximum length of the wear track is thus 807 mm (10 tracks X 75mm in the x direction plus 9 tracks X 6.35mm in the y direction). Because the pin is rotating the wear should be greater than the non-rotating. The maximum velocity of the x and y-axis stages is 10 mm/sec. Because the pin is rotating the wear should be greater than non-rotating. UMT Hardware Configuration for Rotating Pin-on-Flat: Model USMHH Upper Rotational Drive Model DFH-10 Dual Friction/Load Sensor (internal to Upper Rotational Drive) - range 1 N to 100 N for sensors mod. DFH - PN BM Abrasive Sheet with Adhesive Backing Lateral Positioning and Sliding Drive - Mod. LWY-M - mod AE-5 Acoustic Emissions Sensor UMT Software Test Setup for Rotating Pin-on-Flat: Load the options file that contains settings for the Lateral Positioning and Sliding Drive for spindle 1, and the Upper Rotational Drive with internal 100 N force/load sensor for spindle 2. Use the Semi-Automatic Mode to pre-position the x-axis stage so that the pin is 5 mm from the right hand edge of the abrasive sheet. Pre-position the y-axis stage so that the pin is 5 mm from the back edge of the abrasive sheet. This will be the start of a non-overlapping wear track with a length of m. Because the pin is rotating, its wear is typically greater than that in the previous non-rotating pin test. Test Sequence: The Test Sequence should consist of 20 sheets. Spindle1 Velocity is 0 revs/min. Spindle2 Velocity is 0 revs/min. Sheet 2 moves the pin from right to left 75mm. Spindle1 Velocity is 0 rev. /min, Move-Continuous, and Direction- Clockwise Stage Working Velocity is 10 mm/sec., Initial Positioning Velocity is 2 mm/sec., and Position is Increment Offset 75 mm., Check Move immediately, Direction Left. Sheet 3 moves the pin from back to front 6.35mm. Spindle1 Velocity is 600 rev. /min, Move-Increment, Distance 6.35 rev. and Direction- Clockwise Sheet 4 moves the pin from left to right 75mm. Spindle1 Velocity is 0 rev. /min, Move-Continuous, and Direction- Clockwise Stage Working Velocity is 10 mm/sec., Initial Positioning Velocity is 2 mm/sec., and Position is Increment Offset 75 mm., Check Move Immediately, Direction right. Sheet 5 moves the pin from back to front 6.35mm. Spindle1 Velocity is 600 rev. /min, Move-Increment, Distance 6.35 rev. and Direction- Clockwise Repeat sheets 2 through 5 three more times, and then sheets 2 through 4 one time by doing copy and paste for a total of 20 sheets. Page 7