Lithium is a soft metal, with a Young’s modulus in the range of 5 – 8 GPa. Yield strength is about 0.6 – 0.8 MPa. Elongation is about 50%. Therefore it is plastically deformed at very low stress levels. When exposed to air it will immediately oxidize to Li2O which is a brittle ceramic. Li will oxidize even at very low oxygen partial pressures (~10-40 bar). Therefore, if lithium is used as a solid state lubricant to reduce the friction between two mating surfaces, the lithium needs to be coated with an impervious layer of lubricant that completely prevents oxidation of lithium. Formation of Li2O will cause scoring of the surface.

Quite simply, 2-stroke engine have a power stroke for each revolution, whereas a 4-stroke engine has a power stroke every other revolution.  This results in more power for a given displacement but higher average loads on their parts.

If you are making and oil selections for best performance on Hydraulic Oil  (A,B, C etc…) I recommend you to divide the research process in 3 set of assessment.
1- Lab test (See all the previous recommendations above)
2- Bench Test
3-Field test. (Tis is the most important)

V.I. is like a crossed polymer who contracts with low temperature and expand with high temperatures, the objective of this behavior is to keep the viscosity index constant in a range of temperature when the motor is working.

We have found some composite panels which become delaminated due to the intrusion of gear oil applied during machine maintenance, between the plastic & aluminium coil. We’ve already confirmed the same through FT-IR.