Lube-Tech
(Mo-AMIDE) is sulphur free, and is based on the same naturally sourced C12
[22]. The second molybdate friction modifier contains sulphur and is a molybdenum dithiocarbamate (Mo-DTC) similar to that described in EU Patent 2697342 [23].
Experimental
A base electric vehicle style formulation was prepared using a low viscosity Group IV PAO 4cSt base stock. The formulation contained a partial package of additives typically found in an EV or automatic transmission fluid. This formulation was topped with combinations of the three friction and wear modifiers as described in TABLE 1. Each additive is charged within a typical concentration range used in ICE formulations.
ligand chemistry as the B-AMIDE
PUBLISHED BY LUBE: THE EUROPEAN LUBRICANTS INDUSTRY MAGAZINE
No.151 page 3
Figure 1: Composition of ternary mixtures. Table 1: Friction modifiers and concentrations.
The additive combinations used in this study are shown in [Figure 1], with minimum and maximum values of each additive representing the range of 0% to 100% charge. Formulations A through C represent singular component top-treats. Formulations D through F represent binary component top-treats, and formulations G through I represent ternary component top-treats to the base formulation and package.
In addition to testing freshly prepared samples, lubricant samples were also aged by a bulk oxidation method of 48 hours at 160 °C under an oxygen bubble. This was done to simulate oil after an extended in-use period.
Extended Copper Strip Corrosion (CSC) testing was performed on fresh oils in a modified ASTM D130 test, with separate tests running at 24, 168, and 336 hours at 160 °C, and including ICP analysis of solvated copper from each run. Bulk electrical conductivity was measured using an Epsilon+ dielectric meter in a temperature range of 40 -160 °C. Mini-Traction Machine (MTM) Stribeck curves were obtained using a 35 N load, 100% SRR, and 3-3000 mm/s rolling speed, and in temperature steps from 40 -140 °C, in 20 °C increments, with reporting of the average of triplicate measurements at each temperature.
SRV was run using a custom profile of 4N, 1mm stroke, ball on disc, reciprocating at 50Hz. A temperature ramp was imposed from 40°C to 140°C with 10 minutes rubbing at each temperature followed by a 5 minute temperature ramp. Rubbing time was extended to 15 minutes at the final 140°C. Wear scars on the test pieces were then measured using an optical profilometer.
Results and Discussion Extended Cu Corrosion (Modified ASTM D130) The ICP results of the extended copper corrosion [Figure 2] show the increasing solubilised Cu with increasing time. Copper leaching is relatively low (max
LUBE MAGAZINE NO.180 APRIL 2024 29
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60
