Mar 5, 2003 Residual Stress Report Phase II focus area - 2003 Residual stress targeting Heat treatment Materials – composition and strength Die coatings & surface treatments H-13

Residual Stress Taskforce March 5, 2002 Report Phase II Participants Dave Thomason – Pace Mo Vince Adkar - Thyssen Curt Kyonka – Pace mo James Pineault – Proto Mfg. Michael Brauss – Proto mfg. Dr. David Schwam – Case Western Jerry Skoff – Badger Metal Tech

Long Term Goals Of The Develop means to predict and reduce the softening effect during production cycling to improve die life build-up of residual stresses that contribute to premature failure of die tooling

Residual Stress Taskforce Facilitators Case Western Reserve University Proto Manufacturing Pace Industries (beyond baseline) Badger Metal Tech, Inc.

Residual Stress Task Force Approach Develop baseline lab data using x-ray diffraction measuring. Test on production dies Determine threshold values to indicate when die maintenance or corrective action is needed

Residual Stress Task History Developing baseline lab stress data that will be confirmed in the field Some x-ray measurements recorded Tests on 2 Production dies (MN and MO) that did not support expectations. Baseline testing may help support earlier data. Unsuccessful in determining failure threshold on any production dies

Hypothesis I - Cycling Tensile stresses build until they are relieved by development of small micro-cracking Tensile readings drop after this and then stress BUILDS again. Once again cracking develops and TENSILE again dropS in value. (CONTINUE UNTIL VISIBLE CRACKING) If this is true, READINGS will show a cyclic decrease in tensile stress because of the above phenomenon.

Hypothesis iI - Flex THE NORMAL CYCLING OF THE DIE PUTS THE DIE THROUGH TENSION AND COMPRESSION values The acceptable and followed current consensus is that tensile stress causes thermal cracking and failure THIS CYCLING, EVEN THOUGH NOT MAXIMIZED EVENTUALLY CAUSES THE DIE TO UPSET

Hypothesis iII - Decarb The generation of continued cyclic high temperatures cause a loss of carbon at the surface (decarb) The die softens and loses toughness due to the decarb Continued temperature cycling results in build-up of tensile stresses Yield is exceeded and die surface upsets

All corners square +.003” to -.003” All corners have .010” radius Baseline Testing Pre - Dip tank testing virgin specimen nothing applied thoroughly polished send to proto for x-ray diffraction corner measurements case western specified where proto was to take measurements baseline measurements taken H-13 Dip Tank Specimen 2” each side 7” All corners square +.003” to -.003” All corners have .010” radius

Cycling & measurement Dip tank testing Immersion aluminum 12 seconds immersion 24 seconds air cool Water based lube 50:1 Repetitive cycles X-ray diffraction measure Take micro hardness before and after readings measure for corner cracks Photograph x-ray MEASURED surface area H-13 Dip Tank Specimen 2” each side 7” Photography not performed on this 1st specimen All corners square +.003” to -.003” All corners have .010” radius

X-Ray Readings Last 06/11/02 Dip Cycle measurement performed at Zero,10,100,500,1000,5000, 10000, 15000 and now will be measured after 20000 cycles Current Data lent itself to a 20000-30000 cycle measurement, specimen now has 20000 cycles on it but not measured yet.

Proto X-Ray Reading Criteria location measurements Corners 1,2,3,4,5,6,7,8 Middle – 1,3,5,7 Each corner measured at 3 points Each middle measured at 3 points 45o at point #2 (middle) – only for zero cycles Measurements in ksi -1ksi = 6.895Mpa Error range ∓ 5 with average ∓ 2 (zero-1000) Error range ∓ 8 with average ∓ 5 (5000 cycles) Error range ∓ 8 with average ∓ 4 (10,000 cycles) Error range ∓ 2 with average ∓ 1 (15,000 cycle)

Phase ii – Baseline Testing Side 5 Side 7 Side 3 Measured corners 6ea per side x 4 = 24 points Measured middle side 1,3,5,7 Axial 3ea per side x 4 = 12 Trans 3ea per side x 4 = 12 Total of 48 x-ray diffraction measurements from 36 locations Side 1 3.5” 2” each side H-13 Dip Tank Specimen 1” .5” 3.5” 1.0” All corners square +.003” to -.003” All corners have .010” radius

No Dip Cycles - Baseline All but 4 measurements indicate compression

Compressive Stress turns to Tensile 10 Cycles Compressive Stress turns to Tensile

Tensile stress values reduced 100 Cycles Tensile stress values reduced

Tensile stress again increasing 500 Cycles Tensile stress again increasing

Tensile stress approaching values seen at 10 cycles

Tensile stress continuing to increase 5000 Cycles Tensile stress continuing to increase

Tensile stresses at highest levels 10000 Cycles Tensile stresses at highest levels

Tensile stress drop off again – by larger amount 15000 Cycles Tensile stress drop off again – by larger amount

Measurements to be taken at this cycle point 20000 Cycles Measurements to be taken at this cycle point Proto will measure Die Materials Meeting March 5, 2003

SUMATION CURVES and Individual through 15,000 Stress v/s Cycles Normal Stress v/s Cycles Logarithmic (cannot be zero)

What do we know ? Cycling of tensile stresses starting small compression changes rapidly to tensile stresses increase between 100 & 10000 cycles Tensile stress reading at 15000 dramatically drops data could support one or combination of hypothesis

Conclusions will continue to measure at 20K and 30K more test specimens measure dislocation densities via peak width micro hardness changes (multiple specimens) measure corner cracking (before 1st and after)

Future Lab Testing Last at Case - 1/31/2003 Will perform additional testing? Go beyond the 20,000 dips? Measure corner cracking Important not to polish or change stress profile

Future Field Test Parameters No polishing or other modifications to tooling during test cycles Micro-analysis of surface for cracks Shorter measurement cycles Last shot castings should accompany dies and be retained for comparison at case western Micro-hardness readings

Mar 5, 2003 Residual Stress Report baseline testing H-13