ASTM D5707 Standard Test Method for Measuring Friction and Wear Properties of Lubricating Grease Using a High-Frequency, Linear-Oscillation (SRV) Test Machine
4. Summary of Test Method
4.1 This test method is performed on an SRV test machine using a test ball oscillated under constant load against a test disk.
NOTE 2 - The frequency of oscillation, stroke length, test temperature, test load, and test ball and disk material can be varied from those specified in this test method. The test ball yields Hertzian point contact geometry. To obtain line or area contact, test pieces ofdiffering configurations can be substituted for the test ball.
4.2 The wear scar on the test ball and coefficient of friction are measured. If a profilometer is available, a trace of the wear scar on the test disk can also be used to obtain additional wear information in order to calculate the wear volumes of ball and disk by using Practice D7755 or DIN 51834, part 3.
5. Significance and Use
5.1 This test method can be used to determine wear properties and coefficient of friction of lubricating greases at selected temperatures and loads specified for use in applications where high-speed vibrational or start-stop motions are present for extended periods oftime under initial high Hertzian point contact pressures. This test method has found application in qualifying lubricating greases used in constant velocity joints of front-wheel-drive automobiles and for lubricating greases used in roller bearings. Users ofthis test method should determine whether results correlate with field performance or other applications.
