Wear Behaviour of Binary Oil Mixtures Under Extreme-Pressure Conditions

This work presents and discusses the extreme-pressure properties of binary oil mixtures made with a low viscosity polyalphaolefin (PAO 6) and two esters (TMP-05 and sunflower oil, SO). Tests were made in a four-ball machine tester using the ASTM D 2783-88. The ball test material was AISI 52100 steel, 12.7 mm. in diameter, with a hardness of about 65 HRC. The wear scar diameter (WSD) was measured with an optical microscope. The results showed that: although PAO 6, TMP-05 and SO have different physical properties, they perform similar behavior under high loads; TMP-05 and SO have better results in wear tests than PAO 6, but their extreme-pressure properties are similar; and TMP-05 and SO act as wear reducers when they are added to PAO 6, but they do not improve its behavior under high loads.