2。11 Loading schedule used in scuffing tests 31

2。12 An example Tt measurement during a scuffing test exhibiting a spike due to onset of scuffing failure 32

2。13 A disk and roller specimen shown as being measured on the gear CMM 35

2。14 A disk and roller specimen shown as being measured on the surface roughness       profiler 36

3。1 Traction repeatability tests performed on HP specimens    。44

3。2 Comparison of the measured µ values of ground, CP and HP surfaces for             

and     values of 5 m/s, 10 m/s, and 15 m/s。 Oil is MIL-PRF-23699 46

3。3 Comparison of the measured µ values of ground, CP and HP surfaces for             

and     values of 5 m/s, 10 m/s, and 15 m/s。 Oil is MIL-PRF-23699 47

3。4 Comparison of the measured µ values of ground, CP and NiB coated surfaces for

              and     values of 5 m/s, 10 m/s, and 15 m/s。 Oil is 80W90 49

3。5 Comparison of the measured µ values of ground, CP and NiB coated surfaces for

              and     values of 5 m/s, 10 m/s, and 15 m/s。 Oil is 80W90 50

3。6 Measured roller axial profile traces after 30 million cycles wear test; CP specimens with MIL-PRF-23699, HP specimens with MIL-PRF-23699, and CP specimens

with 80W90 52

3。7 Measured roller axial profile traces from a wear test with NiB coated specimens and 80W90 oil at 0 (initial surface), 2 million, 4 million, 5 million, and 10 million cycles 53

3。8 Comparison of initial and 10-million-cycle axial profiles of NiB coated roller and disk specimens 55

3。9 Digital images of NiB coated disk and roller specimens after 10 million roller wear Cycles 57

3。10 Digital images of NiB coated roller after 10 million roller wear cycles at 10x magnification and 20x magnification 58

3。11 Measured surface bulk temperature of rollers during the scuffing test with 9310 specimens with ground, HP and CP surfaces under full and starved MIL-PRF-23699 lubricant conditions 61

3。12 Measured traction torques during the scuffing test with 9310 specimens with ground, HP and CP surfaces under full and starved MIL-PRF-23699 lubricant conditions 62

3。13 Digital images of scuffing tests with MIL-PRF-23699 oil under full lubrication conditions; ground, chemically polished and highly polished specimens