May 19, 2005  

Dr. David Krus
Brush Wellman Inc.
1776 Clair Ave.
Cleveland, Ohio 44110

Re:  Evaluation of Toughmet CX105 Sliding Against Metalife Coated AISI 8620 Steel. 

Dear Dave: 

We have completed the tests on the Metalife coated samples and find the results to be
encouraging. Four tests were run on the coating against Toughmet alloy. Two were journal
bearing tests and two were thrust washer tests. One of each test was run lubricated and one was
run unlubricated. 

Test Conditions

The test conditions were as follows:
 

Journal Bearing Test, PV Limit Test

            Materials   - Toughmet CX105 vs

                             - Case 60 shafting coated with metalife     

            Surface Roughness
                              Bearing     - 32.2 to 39.6 u" Ra
                              Shaft         - 12.6 to 15.5 u" Ra 

            Bearing Size    - 1'' OD X 1" long 

            Contact Area    - 1.0 sq. inch (Projected Area) 

            Load                 - 50 psi increments to failure 

            Velocity            - 100 to 600 ft/min 

            Lubricant

                   Test 1 - Dry
                   Test 2 - Quaker State SAE 10W - HD 

            Temperature - 72ºF at the start

Thrust Washing Wear Test

             Material
                   Rotating Sample   - Toughmet CX105

                  Stationary              - AISI 8620 Case
                                                 Carburized to 60 to 64 RC, surface coated with Metalife system

             Surface Roughness

                   Toughmet             - 31.6 to 37.4 u" Ra
                   Steel                      - 10.7 to 12.6 u" Ra

             Contact Area               - .2 sq. inches

             Velocity                       - 100 ft/min

             Load                             - 20 lbs, 100 psi

             PV Level                      - 10,000        

             Lubricant
                    Test l                      - Dry
                    Test 2                    - Mobilith SHC 460 grease

             Temperature                - 72ºF at the start

             Test Duration               - 20 hrs.        

Test Procedure

Journal Bearing PV Limit Test
   The test procedure was as follows:
    -    Wipe excess liquid from the Metalife coated steel samples
    -    Measure surface roughness, in u" Ra, on the Form Talysurf
    -    Install the bearing and shaft in the LFW 5 (Falex #5) Journal bearing test apparatus
    -    Apply load and start the shaft rotating at 100 ft/min
    -    Run for 30 minutes and measure friction force and bearing temperatures

            -  Increase load and run for an additional 30 minutes        

            -  Continue the previous 2 steps until failure. During this process when the load capacity of
                the test apparatus was reached, the velocity was increased to 200, 300 etc. ft/min in order
                to increase the PV value         

            -  At failure the test rig was allowed to cool and disassembled        

            -  The surface roughness of the contact area was re-measured        

            -  Take macrophotographs of the bearing and shaft 

Failure was determined by the bearing smoking and increased friction 

Test Procedure        

       Thrust Washer Wear Test.       

       The test procedure was as follows:        

            - Clean rotating sample in reagent grade methanol and wipe excess fluid off the metalife

              coated sample        

            - Weight samples on an analytical capable of 4 decimal places in grams        

            - Measure surface roughness of the sample in u" Ra on a Form Talysurf        

            - Assemble test samples in the LFW6 (Falex #6) thrust washer test apparatus apply grease
              where necessary        

            - Apply load and start test rig        

            - Allow test rig to run for 20 hours and measure friction force and temperature        

            - At the end of 20 hours, store test rig        

            - Reclean and reweigh samples        

            - Remeasure surface roughness        

            - Take macrophotographs of the test samples        

     Test Results        

    Table I & II show the results of this evaluation.

         The PV limit for the combination was 31,000 in the unlubricated condition and 360,000 PV for
         the lubricated condition. The dry friction coefficient was .29 and the lubricated value was .02.
         The maximum temperature was 420ºF for the unlubricated condition and 213ºF for the lubricated
         condition.

         There was slight damage to the bearing and shaft in the unlubricated condition and little to no
         damage in the lubricated condition.        

        Table II shows the results of the thrust washer wear tests. The friction coefficient in the
         unlubricated condition was .13 and in the lubricated condition was .08. The maximum
         temperature was 475ºF for the unlubricated condition and 313ºF for the lubrication test.

         The wear rate for the unlubricated condition was 3.2 mg/hr and less than < 0.1 mg/hr for the
         lubricated test. Slight damage was noted on the unlubricated sample surface and very little
         damage was obvious on the lubricated sample.

         Conclusions

         The overall results for the Metalife coated samples show a considerable increase in PV limit
         when compared to previous tests run on uncoated samples. Similar comparisons to uncoated
         wear tests indicate that the wear rate was reduced significantly when coated with the metalife
         system.

         If you have any questions, please do not hesitate to call me.

         Sincerely,

       
         Salvadore J. Calabrese
         Research Specialist

Rensselaer Polytechnic Institute
110 8^th Street │Troy, NY 12180-3590 USA

Table 1 - Metalife Coating

Table II - Metalife Coating
Thrust Washer Wear Test

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