This standard specifies the test method for the friction and wear performance of sintered metal friction materials in the absence of oil lubrication. JB/T 7269-1994 Dry sintered metal friction material friction performance test method JB/T7269-1994 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
JB/T7269-94Www.bzxZ.net
Dry Sintered Metal Friction Material
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
Dry Sintered Metal Friction Material
Friction Performance Test Method
Subject Content and Scope of Application
This standard specifies the test method for the friction and wear performance of sintered metal friction materials under oil-free lubrication. This standard is applicable to the determination of dynamic and static friction coefficients and wear rates of dry sintered metal friction materials by testing machine method. 2 Terms
2:1 Duality
Metal parts that form friction pairs with the same friction material. Apparent area of ​​the specimen
The area of ​​the single surface of the friction specimen after deducting the area of ​​the grooves, holes, etc. from the area of ​​the specimen ring. 2.3 Apparent specific pressure
The surface unit pressure obtained by the apparent area of ​​the sample. 2.4 Unit friction work
The friction work generated per unit apparent area of ​​the friction pair during the joining process. 2.5 Unit friction power
The friction work generated per unit apparent area and per unit time of the friction pair during the joining process. 3 Test device
3.1MM-1000 friction and wear testing machine. 3.2 In addition to the torque recording system with an appropriate range, the testing machine must also be equipped with a device for recording pressure changes. 4 Test specimens
Sintered metal friction materials and dual specimens are shown in Figures 1 and 2. 4.12
4.2 The specimens can be cut from the product or made by the same process. 4.3 The technical requirements of the dual material depend on the working conditions. Approved by the Ministry of Machinery Industry on June 18, 1994
JB/T7269-94
Implemented on January 1, 1995
JB/T 726994
Figure 1 Material specimen
Figure 2 Dual specimen
Test conditions
The test conditions should meet the requirements of Table 1.
Linear speed√
Apparent specific pressure
Rotation
Joining rate
Test method
Run-in according to the requirements of Table 2.
Linear speed?
Apparent specific pressure P
Moment of inertia 1
JB/T 726994
1X16kgm
Times/min
1×10kgm
When the friction pair joint area reaches 75% of the total area, the running-in is completed. 6.1.2
6.1.3Measure the thickness of three points at an interval of 120° at the average radius of the friction plate and the mating plate. Determination of static friction torque
After running-in, apply a pressure of 0.7MPa, move the main shaft, measure the static torque three times and take the average value. 6.3 Determination of friction coefficient
According to the test conditions in Table 1, engage 100 times. Record the torque and pressure characteristic curves of the 1st, 25th, 50th, 75th and 100th engagement processes. Calculation method
Static friction coefficient
Where:—
Static friction coefficient:
MStatic friction torque, N·m;
Pz——Total pressure acting on the apparent surface of the sample, N; Rj——Average radius of the sample, cm.
7.2 Friction coefficient
Where:
Average friction coefficient:
Average torque, N·m.
Reported results are rounded to 0.01.
Friction work
W=Mest
Where: W-Friction work, N·m;
-Average angular velocity, r/s;
t—Joining time, s.
Determination of wear rate
JB/T7269-94
After 100 times of engagement, measure the wear of the original corresponding points of the specimen and calculate the wear rate. Calculation method
Wherein: 8-
wear rate, cm*/(N·m);
wear volume of specimen, cm;
Hlinear wear volume of specimen, cm;
friction area of ​​specimen, cm;
accumulated friction work, N·m.
Test report
The test report should include the following contents:
Test conditions;
dynamic and static friction coefficients;
wear rate:
friction surface conditions;
original conditions of specimens;
abnormal conditions during the test.
Additional Notes:
This standard was proposed and coordinated by Beijing Powder Metallurgy Research Institute. This standard was drafted by Beijing Powder Metallurgy Research Institute. The main drafters of this standard are Pang Shidiao, Li Mulin, Ni Xiaobao, Chu Yuanjie and Hu Qing. 4
(4)
People's Republic of China
Mechanical Industry Standards
Dry Sintered Metal Friction Material
Rate Friction Performance Test Method
JB/T7269-94
Published and distributed by the Machinery Standardization Research Institute of the Ministry of Machinery Industry Printed by the Machinery Standardization Research Institute of the Ministry of Machinery Industry (P.O. Box 8144, Beijing
Copyright reserved||tt| |Postal code 100081)
No reproduction
Word count 6,000
Format 880×12301/16
Printing sheet 1/2
First edition in May 1995
First printing in May 1995
Print count 00,001500
Price 3.00 yuan
No. 94--155
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