1.1 This test method covers laboratory procedures for determining the coefficient of friction and resistance of materials to adhesive wear under flat sliding using the twist compression test (TCT). It is the intent of this test method to produce data that will provide fundamental friction data and reproducibly rank materials and surface treatments in their resistance to adhesive wear under a specified set of conditions. 1.2 Adhesive wear test results are reported as time until adhesive failure for the particular test procedure is specified. Materials of higher adhesive wear resistance will have a greater time until failure. The wear resistance may be inherent in the material properties or develop as a tribofilm that blocks the mechanism of adhesion. NOTE 1--Failure criteria may vary depending on the industrial application being modeled in the TCT. In comparing results between laboratories, it is critical that materials and surface preparation, lubricants, and test conditions are the same. 1.3 This test method covers three recommended procedures that use different failure criteria. 1.3.1 Procedure A--A relatively severe test that will rank materials on a time-until-failure condition with failure identified by a sustained rise in the coefficient of friction after a period of stability (the test is usually terminated by the operator). Adhesive wear is confirmed by examining the test specimens upon completion of the test. 1.3.2 Procedure B-This test, like Procedure A, continues until the coefficient of friction exceeds a predetermined threshold limit (that is, 0.2). The threshold will depend on the materials, sliding velocity, and contact pressure. (With some software programs, the test is terminated at the threshold coefficient of friction by the preset value in data acquisition system.) 1.3.3 Procedure C-Procedure C is an interrupted test performed to preserve the contacting surfaces at a time of interest. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
This test is widely used to evaluate the tendency for surfaces to suffer from adhesive wear on both lubricated and unlubricated surfaces. It will be used to compare materials and surface treatments.
Keywordsadhesive wear; galling; scuffing, scoring; plowing; metal working; forming
The title and scope are in draft form and are under development within this ASTM Committee.Back to Top
Draft Under Development