ASTM D7217 Standard Test Method for Determining Extreme Pressure Properties of Solid Bonded Films Using a High-Frequency, Linear-Oscillation (SRV) Test Machine
10. Report
10.1 Report the following information:
10.1.1 Report all parameters used to evaluate material as follows:
10.1.1.1 Temperature, °C,
10.1.1.2 Stroke, mm,
10.1.1.3 Frequency, Hz,
10.1.1.4 Relative humidity in %,
10.1.1.5 Load step interval in seconds,
10.1.1.6 Test ball material,
10.1.1.7 Test disk material,
10.1.1.8 Solid bonded film test coating, and
10.1.1.9 Pretreatment of disk.
NOTE 11 - Pretreatment can consist of sandblasting followed by phosphate treatment (manganese, zinc, or iron base).
NOTE 12 - As especially under unlubricated conditions the tribological properties depend on the relative humidity of the surrounding air, this test quantity has to be reported or controlled.
10.2 Report the highest test load (pass load) at which no seizure occurred.
11. Precision and Bias
11.1 Ten cooperators tested two different, commercial available solid bonded films at one temperature using three different times for load increase of 1 min, 3 min, and 6 min and 10 mm balls and flat disks using AISI 52100 (100Cr6H) in repeated tests. A poly(amidimid) bonded, MoS 2 containing SBF was supplied by SBF1 and a "white" PTFE-containing SBF by SBF2. The cooperators reported relative humidities between 40 % and 50 %. All disks were sand blasted (Frigosit 100 mesh) and phosphated. ADJD6300 (D2PP software) was used for the statistical analysis of the data.
11.2 The following criteria should be used for judging the acceptability of results (95 % probability) for solid bonded films, which have load carrying capacities of up to 4000 MPa or less in the SRV apparatus using an oscillating frequency of 20 Hz, a temperature of 50 °C and 2 mm of stroke (see Appendix X1).
11.2.1 Repeatability - The difference between successive results obtained by the same operator with the same apparatus under constant operating conditions on identical test material would, in the long run, in the normal and correct operation of the test method exceed the following values only in one case in twenty.
for tests run with 1 min: 0.25 X
for tests run with 3 min: 0.44 X
for tests run with 6 min: 0.45 X
where:
X = the average of two results, N.
11.2.2 Reproducibility - The difference between two single and independent results obtained by different operators working in different laboratories on identical test materials would, in the long run, exceed the following values only in one case in twenty.
for tests run with 1 min: 0.85 X
for tests run with 3 min: 0.48 X
for tests run with 6 min: 0.29 X
where:
X = the average of two results, N.
11.3 Bias - The evaluation of load-carrying capacity of lubricating grease by this test method has no bias because load-carrying capacity can be defined only in terms of the test method.
12. Keywords
12.1 extreme pressure; load-carrying capacity; oscillating; solid bonded film; solid film lubricant; SRV
