Experimental results of the tribology of aluminum measured with a pin-on-disk tribometer: Testing configuration and additive effects

摘要

The friction coefficient, wear rate, and wear coefficient of the aluminum metal surface were measured at room temperature (≈300 K) with a pin-on-disk machine at a fixed load of 196.2 N. Two different testing configurations were adopted: (1) aluminum pin vs. Helix oil-on-steel disk (AHS) and (2) aluminum pin vs. 10% Polytron plus 90% helix oil-on-steel disk (APS). In the AHS configuration, the wear of the aluminum surface was found to be approximately 70 μm; however, in the APS configuration the wear dropped to 20 μm, revealing a marked decrement of one-third of the wear of aluminum. The volume wear rate of the metal in the unaided Helix oil was estimated to be 1.28×10~(-3) mm~3/min. The additive minimized the volume wear rate of the aluminum metal by orders of magnitude to 6.08×10~(-5) mm~3/min. Similarly, the wear coefficient of the aluminum pin, calculated in the AHS configuration, rendered a value of 1.27×10~(-10) m~2/N. In the APS configuration, the same parameter was 4.22×10~(-11) m~2/N, that is to say, an order of magnitude lower than the preceding value. The observed coefficient of friction for aluminum is 0.012 in Helix oil and falls to a remarkably lower value of 0.004 through the Polytron additive. The experimental findings demonstrate that Polytron additive substantially lessens the wear of the aluminum surface; in effect, the wear coefficient and the wear rate decline linearly. This singularity may be linked to the ability of Polytron to impregnate the crystal structure of the metal due to its ionic character and the consequent adherence to the metallic surface as a hard surface layer.