This standard specifies the test method for the friction and wear performance of wet sintered metal friction materials in a specific friction pair under oil lubrication conditions. This standard is applicable to the determination of dynamic and static friction coefficients and wear rates of wet sintered metal friction materials by testing machine method. JB/T 7268-1994 Test method for friction performance of wet sintered metal friction materials JB/T7268-1994 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
JB/T7268-94
Wet Sintered Metal Friction Materials
Friction Performance Test Method
Published on June 18, 1994
Ministry of Machinery Industry of the People's Republic of China
Implemented on January 1, 1995
Mechanical Industry Standard of the People's Republic of China
Wet Sintered Metal Friction Materials
Friction Performance Test Method
1 Subject Content and Scope of Application
JB/T7268-94
This standard specifies the test method for the friction wear performance of wet sintered metal friction materials in a specific friction pair under oil lubrication conditions.
This standard is applicable to the determination of dynamic and static friction coefficients and wear rates of wet sintered metal friction materials by testing machine method. ,2Terms
2.1 Duality
Metal parts of the friction pair made of the same friction material. 2.2 Apparent area of ​​the specimen
The area of ​​the single surface of the friction specimen after deducting the area of ​​the oil groove, screw hole, etc. from the area of ​​the specimen ring. 2.3 Apparent specific pressure
The surface unit pressure obtained according to the apparent area of ​​the specimen. 2.4 Burn
The "welding point" formed due to the adhesion of the friction interface during the friction process. 2.5 Material transfer
The surface diffusion phenomenon of the friction pair that occurs on the friction surface during the friction process. 2.6 Unit friction work
The friction work generated by the friction pair per unit apparent area during the joining process. 2.7 Unit friction power
The friction work generated by the friction pair per unit apparent area and per unit time during the joining process. Test load
The test was carried out on a MM-1000 friction and wear tester equipped with an MM-15 multi-plate test chamber. In addition to a torque recording system with an appropriate range, the test machine must also be equipped with a device for recording and measuring pressure changes. 3.1 Requirements
3.1.1 Relative speed 15m/s to 0.
3.1.2 Control two cycles per minute.
3.1.3 The measuring device should be able to measure relative speed, pressure, torque, engagement time, and lubricating oil temperature. 3.1.4 The lubrication system provides sufficient heat exchange capacity, and the lubricating oil temperature in the oil tank is controlled at 60±10℃. 4 Lubricating oil
4.1 10W-30 engine oil, No. 6 torque converter oil or other specified oil types. 4.2 The same oil type must be used for comparative tests. Approved by the Ministry of Machinery Industry on June 18, 1994
Implemented on January 1, 1995
5 Preparation of test specimens
JB/T7268--94
The test specimens shall be cut directly from the product or prepared under the same process conditions as the product. 5.1
The dimensions of the test specimens shall comply with the provisions of Figure 1, and any specified test specimen may be used. 5.2
5-6 Spread evenly
ssei.re.s
Oil magnification
2.5±0.02
5.3 The dimensions of the dual sheet shall comply with the provisions of Figure 2, and any specified sheet may be used. + 66+81
90'0*T
Technical requirements
Heat treatment hardness: 2833HRC
5.4 Measure the thickness of the friction plate and the mating plate at three points with an interval of 120° on the circumference of the average radius. 6 Test conditions
The test conditions shall comply with the requirements of Table 1.
Pressure angle
Pressure angle
Involute
Involute
Linear speed√
Apparent specific pressure p
Moment of inertia 1
Joining rate
Lubricating oil
Oil flow
Number of engagements
Test steps
7.1 Running-in
JB/T7268-94
1×10kg*m
Times/min
mL/(min·cm*)
The friction plate and the mating plate are placed in the test box. 7.1.1
Run-in according to the requirements of Table 2.
Speed ​​n
Apparent specific pressure p
Moment of inertia 1
Oil flow Q
1×10kgm
mL/(min ·cm)
10W-30, No. 6 torque converter oil
60±10
7.1.3Record the torque after 100 engagements. Measure the friction coefficient every 50 times. When the friction coefficient of the latter stage differs from that of the previous stage by 10%, the running-in is considered complete.
7.2 Static torque measurement
Measure after running-in. Remove the pressure, apply an apparent specific pressure of 0.7MPa after 60s, move the spindle, and measure the static torque three times. 7.3 Determination of friction coefficient
According to the test conditions in Table 1, engage 100 times and record the torque and pressure characteristic curves of the 1st, 25th, 50th, 75th and 100th engagement processes. 8 Analysis of test results
8.1 The friction material surface should not have defects such as pits, cracks or material transfer. There is no material transfer or burn on the dual plate. Some area discoloration is allowed, but the surface should be smooth.
8.2 The tooth shape of the friction plate and the dual plate should not be deformed. 9 Calculation method
Static friction coefficient
Where:
Static friction coefficient:
-static friction torque, N·m;
P2-total pressure acting on the apparent surface of the sample;-average radius of the sample, cm;
+......(1)
i-number of friction surfaces of the sample.
9.2 Friction coefficient
Where: pi--average friction coefficient;
M, j-average torque, N·m.
Calculation of friction work
Where: w
-total friction work, N·m;
average angular velocity, r/s;
-time, s. bzxz.net
Reported results are rounded to 0.0001.
Determination of wear rate
10.1 Method
JB/T7268-94
(3)
According to the test conditions in Table 1, the moment of inertia is reduced to 10×10-2kg·m, and the joints are continuously engaged for 1000 times. The linear wear is measured and the wear rate is calculated.
10.2 Calculation of wear rate 8
- wear rate, cm/(Nm);
Where:-
V- wear volume of specimen, cm;
H- total linear wear of specimen, cm
A-- apparent surface area of ​​specimen, cm;
- accumulated friction work. N·m.
The report result is rounded off to 0.01×10-8
Specific working conditions
Specific working conditions can still be carried out according to the method of this standard. Test report
The test report should include the following contents:
Test conditions;
dynamic and static friction coefficients;
wear rate;
friction surface conditions and phenomena;
original test conditions.
Additional Notes:
This standard was proposed and coordinated by Beijing Powder Metallurgy Research Institute. This standard was drafted by Beijing Powder Metallurgy Research Institute. HA
The main drafters of this standard are Pang Shidiao, Li Mulin, Ni Xiaobao, Lu Naiguang, and Cheng Wengeng. (4)
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