Block-on-ring test

Friction force (ASTM method D2714-the Falex block-on-ring test). The... 

The block-on-disk test (12) is also called a block-on-ring test, but the counterface is not really a ring. It is a 150 mm diameter hardened tool steel disk. 

The previously mentioned tests that can be used to determine if a plastic is abrasive to other surfaces are not particularly suited to evaluation of the abrasivity of plastics that are normally manufactured as flexible webs. Web materials with thicknesses less than about one millimeter pose the problem that they usually need to be adhered to some other surface to allow testing them as bushings, thrust washers, or blocks for block-on-ring tests. This can be done and is done, but two other tests Imve been developed that are particularly useftil for web materials the ball-on-plane test and the tape abrasion test (14). The ball-on-plane test, lich is shown schematically in Figure 8, reciprocates a spherical rider on a web test sample while the sample rotates slowly at less than 1 revolution per minute. The rider would see mostly fresh surface if allowed to run only one revolution, but in practice this test is usually run for longer test durations (from 10 minutes to 40 hours). When the test is run for more than an hour, the web counterface is changed every hour the rider is simply lifted off the test surface. Volume loss on the ball rider is the test metric. Wear volume is measured from the ball scar diameter and this measurement can be made in situ on the test apparatus. 

ASTM G 77, Test Method for Ranking Resistance of Materials to Sliding Wear Using Block-on-Ring Test, ASTM, West Conshohocken, PA, 1994... 

D3704 Test Method for Wear Preventative Properties of Lubricating Greases Using the (Fdex) Block on Ring Test Machine in Oscillating Motion Wear scar width... 

Figure 9, Wear rate of epoxy/Si02 nanocomposites vs. particle content (amine catalyst) (a) fretting test, (b) block-on-ring test.

Figure 10. Scanning electron micrographs of the worn surface of epoxy/SiOj nanocomposite after block-on-ring test (a) pure resin (b) Si022.97 vol.%.

Dimensional wear factors calculated in this work under reciprocating conditions are 1.06x10 -1.18x10 m /Nm (2xl0 -2.22xl0 mVm) for the ZDDP containing lubricant which are similar to those reported from block-on-ring tests in the work of Jahanmir [9]. 

The block on ring tests replicate the contact conditions at particular points in the cam / follower cycle. As such they are the first stage of an experimental programme to investigate the correlations between surface chemistry and tribology in such interfaces. An important second phase will progress to more realistic simulations. 

Conventional wear test configurations can be adapted to fretting. Ball-on-flat, block-on-ring, and crossed cylinders can be modified so that the sliding motion can be made oscillatory and the amplitude small (less than 100 tm). 

Wear Factor Block-on-ring For Laboratory Screening. Test time may be 20h/sample. 

The friction coefficient and the specific wear rate of the nanocomposites were determined by sliding wear tests on a block-on-ring apparatus against a 100 Cr 6 (German standard) steel ring as the counterpart. A pressure of 1 MPa and a velocity of 1 m/s were used over a duration of 20 h for each sample. Additional wear tests of the composite systems were carried out under fretting test conditions against a ceramic ball as the counterpart. 

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