A Metallurgical Comparison of Mack T-12 Rod Bearings. Lots U, V & W

1. A Metallurgical Comparison of Mack T-12 Rod Bearings.Lots U, V & W Characterization by: W.R. Wetsel R&D Application Science Dept. February 23, 2010

2. Introduction: This is a comparison in the construction and metallurgy of Mack T-12 Rod bearings. Lots “U” , “V” and “W” were submitted for evaluation. Method of Characterization: Non-standardized Energy Dispersive Spectroscopy and Scanning Electron Microscopy were used to characterize the submitted bearings. The outer surface and cross-sections were characterized. The various metallic layers were identified for composition and thickness. Upper and lower bearing halves were evaluated from each lot. Findings: All three bearing lots are similar in the various layers of composition and thickness of each layer. The bearings have an outer tin flash coat, an electroplated lead layer containing copper and tin, a nickel diffusion barrier and a copper matrix liner containing lead particles.

3. A word about EDS and sample preparation: The cross-sections were given a metallographic polish consisting of grinding with sandpaper then polishing with 3 um. diamond and 0.05 um. aluminum oxide. Embedded debris from polishing can be detected by EDS. Iron and nickel may be reported at low levels in the electroplated lead and the liner. The various metal layer cross-sections were analyzed using Energy Dispersive Spectroscopy (EDS). Beam spread causes detection of nearby elements that were not intended to be in the analysis. Example: If the electroplated Pb/Sn is being analyzed Ni from the diffuion barrier and Cu from the liner will be picked up.

4. Mack T-12 Rod Bearing Half Shells Elemental Analysis of the External Surfaces Method: Energy Dispersive Non-quantitized Spectrometry (EDS) Data in wt. % The electron beam penetrates through the thin tin electroplate. The EDS results are the flash tin and lead electroplate combined. The high tin levels indicate a tin flash coating.

5. EDS Results on Cross-sections of the Pb-Sn Electroplate Layer Data in wt. %

6. EDS Results on Cross-sections of the Cu-Pb Liner Data in wt. %

7. Thickness Measurements on the Four Metal Layers Units microns * The outer Sn flash plating is very difficult to measure accurately. The edge may be slightly damaged from mechanical polishing. EDS of the outer surface shows similar high levels of Sn.

8. Lot “U” Lower Rod Bearing External Surface EDS Data 100X

9. Lot “U” Lower Bearing Shell Cross-section D steel 100X EDS Data in wt. % • Flash Sn 0.5 um. thick • Pb-Sn electroplate 12.1 um. thick • Ni diffusion layer 1.7 um. thick • Cu-Pb liner 315 um. thick B D The black particles are embedded 3 um. diamond polishing compound. 2000X

10. Lot “U” Upper Rod Bearing External Surface EDS Data 100X

11. Lot “U” Upper Rod Bearing Shell Cross-section D steel 100X EDS Data in wt. % B • Flash Sn 0.06 um. thick • Pb-Sn electroplate 9 um. thick • Ni diffusion layer 1.3 um. thick • Cu-Pb liner 455 um. thick D 2000X

12. Lot “V” Lower Rod Bearing External Surface EDS Data 100X

13. Lot “V” Lower Rod Bearing Cross-section D steel 100X EDS Data in wt. % B • Flash Sn 0.6 um. thick • Pb-Sn electroplate 14 um. thick • Ni diffusion layer 1.6 um. thick • Cu-Pb liner 361 um. thick D 2000X

14. Lot “V” Upper Rod Bearing External Surface EDS Data 100X

15. Lot “V” Upper Rod Bearing Cross-section EDS Data in Wt. % D steel 100X B • Flash Sn 0.2 um. thick • Pb-Sn electroplate 9.5 um. thick • Ni diffusion layer 1.9 um. thick • Cu-Pb liner 390 um. thick D 2000X

18. Lot “W” External Surface Lower Rod Shell SEM Images

19. Lot “W” Lower Rod Shell Cross-sections – SEM Images D 100X steel • Flash Sn 0.3 um. thick • Pb-Sn electroplate 11.8 um. thick • Ni diffusion layer 1.7 um. thick • Cu-Pb liner 342 um. thick B D 2000X

20. Lot “W” Upper Rod Shell 100X

21. Lot “W” Upper Rod Shell D 100X steel • Flash Sn 0.4 um. thick • Pb-Sn electroplate 11.8 um. thick • Ni diffusion layer 0.9 um. thick • Cu-Pb liner 440 um. thick B D 2000X