Primary focus areasPrimary focus areas
Materials – composition and strength
Heat treatmentResidual stressDie coatings & surface treatments
H-13
June 7, 2000 Residual Stress June 7, 2000 Residual Stress ReportReport
Residual stress Task Residual stress Task Force GoalsForce Goals
Develop means to reduce the softening effect during production cycling to improve die life
Develop means to Reduce build-up of residual stresses that contribute to premature failure
Residual stress taskforce Residual stress taskforce Facilitators & participantsFacilitators & participants
Case western reserve university Ast – American stress technologies Pace industries Intermet – Ganton Ford motor company General motors powertrain Badger Metal Tech, Inc.
Residual stress task forceResidual stress task force
approachapproach Develop baseline stress data Must Perform on Production dies Measure with x-ray diffraction and
Barkhausen readings Repeat until stress cracking
initiates Determine threshold values to
indicate when maintenance or corrective action is needed
Current Test Site Current Test Site Pace Industries Pace Industries
MOMOgm – cav 9,10gm – cav 9,10
high volume runner multiple cavities flat surface prone to h/c history of rapid h/c flexible production schedule smaller size inserts for handling reasonable time frame for results approval of end user
Cavity #9
Photos taken during Pace visit
ShotBiscuit
Die Sampled350 SHOTS
Approximate area where X-ray and Barkhausen
measurementsare being taken
Directions#1 0 degrees# 2 -45 degrees# 3 -90 degrees
Prior to 1Prior to 1stst #9 #9
Cavity #10
REAR RETAINERPhotos taken during Pace visit
ShotBiscuit
Die Sampled350 SHOTS
Directions#1 0 degrees# 2 -45 degrees# 3 -90 degrees
Approximate area where X-ray and Barkhausen
measurementsare being taken
Prior to 1Prior to 1stst #10 #10
Residual stressResidual stressfirst measurementfirst measurement
(Die already sampled - 350 (Die already sampled - 350 shots)shots)
Procedure Measurements taken by AST at specified
areas determined by past history and Case Western recommendations
Die X-ray site plotted for future measurements
Barkhausen readings in same locations Inserts returned to Pace for
approximately 20-30K shots Repeat measuring cycle for stress and
Barkhausen readings until steel upsets & heat checking occurs
Second Measurement
Die had 20,523 shots (producing castings (03/29/2000)
(Will attempt to pull every 20-30K- takes 2 weeks)
AST commented that, upon receipt, noted that the calibration area selected on the dies for the 1st measurement appeared to be aggressively ground.
Same reference point used for measurement #1 would make Barkhausen readings (which measures change) not usable.
New calibration piece for reference was made by AST but not from (H-13).
Measurements taken and returned to Pace.
third Measurement Die has 41,209 shots 04-25-00 Measurements taken and returned
to Pace on 05-03-2000.
Trend is Increasing toward zero for Xrd – More compressive ????
decreasing for the bna.
Not what was expected
No physical signs of upset as yet
Date Shots X-Ray (XRD in KSI) Barkhausen (BNA numerical)Measured 0 degrees -45 degrees -90 degrees 0 degrees -45 degrees -90 degrees
Part Cav #9FIRST READ 02/17/2000 350 +33.3 +/- 2.6 +34.8 +/- 1.8 +41.2 +/- 1.6 80.1 97.6 173.3
SECOND 03/14/2000 20,523 +29.3 +/- 1.8 +38.7 +/- 2.1 +50.7 +/- 1.4 52.9* 54.9* 98.4*THIRD 05/02/2000 41,209 + 8.1 +/- 1.9 +17.3 +/- 2.6 +22.7 +/- 2.3 41 40 56
TREND
Part Cav #10FIRST READ 02/17/2000 350 +35.7 +/- 1.6 +40.1 +/- 1.6 +41.0 +/_ 1.2 44.5 81.4 80
SECOND 03/14/2000 20,523 +38.9 +/- 1.8 +59.8 +/- 1.1 +63.9 +/- 1.5 32.4* 64.8* 69*THIRD 05/02/2000 41,209 +28.0 +/- 1.7 +41.7 +/- 1.8 +53.7 +/-1.5 22 40 48
TREND
* The calibration area selected on the dies during run 1 of testing was aggressively ground when the dies .arrived for round #2. A separate calibration piece (not H-13) was created during round 2 that will be kept at AST.
Sensor Units for Barkhausen were same as first time.(Round #2 dies were ground in area where we took reference barkhausen readings)[Barkhausen measures changes - ie: Residual Stresss, Hardness, Micro-structureand outputs it as a numerical value.
Current readingsCurrent readings
trend indicates decreasing tensile stress
InstrumentationInstrumentationInstrumentationInstrumentation
Central UnitCentral UnitCentral UnitCentral UnitSensorSensorSensorSensor
MagnetizeMagnetize
Amplify and Amplify and FilterFilter
ApplyApplyMagnetic Magnetic
FieldField
Detect Detect B-signalB-signalDisplay and Display and
OutputOutput
Barkhausen NoiseBarkhausen Noise
Principle of TestingPrinciple of TestingPrinciple of TestingPrinciple of TestingMagnetizing Magnetizing VoltageVoltageMagnetizing Magnetizing VoltageVoltage
SteeSteellSteeSteell
SensoSensorrSensoSensorr
Central UnitCentral UnitCentral UnitCentral UnitTestTestAreAreaa
TestTestAreAreaa
Barkhausen NoiseBarkhausen Noise
Effect of StressEffect of StressEffect of StressEffect of Stress
LowLowAmplitudeAmplitudeLowLowAmplitudeAmplitude
HighHighAmplitudeAmplitudeHighHighAmplitudeAmplitude
CompressionCompressionCompressionCompression
TensionTensionTensionTension
Amplitude Amplitude StressStress
Amplitude Amplitude StressStress
AmplitudeAmplitudeAmplitudeAmplitude
AA22AA22
AA11AA11
StressStressStressStress
Barkhausen NoiseBarkhausen Noise
Effect of HardnessEffect of HardnessEffect of HardnessEffect of Hardness
LowLowAmplitudeAmplitudeLowLowAmplitudeAmplitude
HighHighAmplitudeAmplitudeHighHighAmplitudeAmplitude
High HardnessHigh HardnessHigh HardnessHigh Hardness
Low HardnessLow HardnessLow HardnessLow Hardness
AmplitudeAmplitudeAmplitudeAmplitude
Amplitude Amplitude HardnessHardness
Amplitude Amplitude HardnessHardness
HardnessHardnessHardnessHardnessRRccRRcc
AA22AA22
Barkhausen NoiseBarkhausen Noise
Recommended and Recommended and Approved for Use byApproved for Use byRecommended and Recommended and
Approved for Use byApproved for Use by SAE - Society of SAE - Society of
automotive automotive
engineeringengineering Department of the Air Department of the Air
ForceForce FAA - Federal Aviation FAA - Federal Aviation
AdministrationAdministration
SAE - Society of SAE - Society of automotive automotive
engineeringengineering Department of the Air Department of the Air
ForceForce FAA - Federal Aviation FAA - Federal Aviation
AdministrationAdministration
Future testing & Future testing & studiesstudies
Continue testing cav #9 & #10Intermet (Ganton) – measure a
four cavity die for ford
Next phaseMetalife, dynablueSurface treatment combinationsVarious coatings – pvd & cvd