DESIGN OF EXPERIMENTS: ANALYSIS MOHAMMAD IRFAN & DAVID SCHWAM

DIE CASTING MECHANICAL PROPERTY IMPROVEMENTS THROUGH PROCESS ENHANCEMENTS MOHAMMAD IRFAN, DAVID SCHWAM (CWRU) ANDY KARVE, RANDY RYDER (NEMAK)

AIM OF THIS LECTURE To show you a short advertisement of the course To show you a preview of what you are going to learn in this course You might not understand all the details of each slide – that is ok To brief you about what is expected from you in your class Mini Project

Needed Stronger and Lighter Engines

SOME FACTORS AFFECTING STRENGTH 1.Chemistry of Molten Metal 2.Plunger Pressure 3.Dwell Time 4.Etc.

DIE CASTING MOVIE

DESIGN OF EXPERIMENTS Process Uncontrollable Factors Questions : 1.Which factors affect the response (output) ? 2.Which factor has the most affect on response ? 3.Which combination of factors have the most desirable effect ? 4.What should be the value of factors to get a certain value of response? Measurable Output Controllable Factors

INPUT AND OUTPUT OF DOE DOE setup to understand the effect of Process Parameters on Mechanical Properties 9 Tensile StrengthYield Strength Cooling (on/ off) Ti Bor (yes/ no) Dwell Time (short / long) Q: How many experiments do we need to conduct to test the effect of 3 input variables on 2 output variables?

DOE MATRIX CoolingTiBorDwell B034 OnNoShort B040 OffYesLong B045OffNoShort B050OnNoLong B055OffYesShort B060OffNoLong B066OnYesLong B071OnYesShort CoolingTiBorDwell B B B B050+1 B055+1 B060 B066+1 B071+1

UTS (SPEC. 200 MPA) CoolingTiBorDwell UTS (MPa) B034 OnNoShort268 B040 OffYesLong251 B045OffNoShort266 B050OnNoLong271 B055OffYesShort263 B060OffNoLong258 B066OnYesLong255 B071OnYesShort265 Average262 Std. Dev.6.8 The UTS values reported for a certain engine block is the average of 8 tensile samples

ANALYSIS OF UTS RESULTS 1.Effect of Cooling Core on UTS = Average of ON values – Average of OFF values = Effect of TiB on UTS = Average of YES values – Average of NO values = Effect of Dwell on UTS (Short Dwell classified as +1) = Average of SHORT values – Average of LONG values = 6.8

ANALYSIS OF UTS RESULTS

YS (SPEC. 150 MPA) VC CoolingTiBorDwell YS (MPa) B034 OnNoShort210 B040 OffYesLong215 B045OffNoShort224 B050OnNoLong209 B055OffYesShort219 B060OffNoLong228 B066OnYesLong215 B071OnYesShort209 Average216 Std. Dev.7.1 The YS values reported for a certain engine block is the average of 8 tensile samples

ANALYSIS OF YS RESULTS 1.Effect of Cooling Core on YS = Average of ON values – Average of OFF values = Effect of TiB on YS = Average of YES values – Average of NO values = Effect of Dwell on YS (Short Dwell classified as +1) = Average of SHORT values – Average of LONG values = -1.3

ANALYSIS OF YS RESULTS

COMMENTS The Std. Dev. in the original data set is in the range of 8 to 30 MPa. It has to be determined through ANOVA (Analysis of Variation) whether the data and the results are statistically significant? Are these the factors we are looking for ? Is either of the factors effecting porosity ? Is there an interaction effect ?

MINI PROJECT Think of an experiment at your workplace Think of the inputs and outputs

DESIGN OF EXPERIMENTS Process Uncontrollable Factors Questions : 1.Which factors affect the response (output) ? 2.Which factor has the most affect on response ? 3.Which combination of factors have the most desirable effect ? 4.What should be the value of factors to get a certain value of response? Measurable Output Controllable Factors

THANK YOU QUESTIONS ?