1. Mohammad Irfan, David Schwam (CWRU) Andy Karve, Randy Ryder (Neemak) Mike Cox, John Kubisch (GM) February, 2009

2.  Part I: Review of Project Brief  Part II: Initial Trials  Part III: EDX & SEM  Part IV: Introduction of cooling core  Part V: DOE  Conclusions  Future Work 2

3. Part - I

4.  DOE setup to understand the effect of Process Parameters on Mechanical Properties of thickest section  Process Parameters: 1. Melt Handling : Melt Temperature, Pour Temperature 2. Injection: Slow shot velocity. Fast shot velocity, intensification pressure 3. Solidification: Die Temperature, Temperature of casting at ejection, Cycle time 4. Water Quench 5. T5 heat treatment 4

5. 5 SeptOctNovDecJanFebMarAprMayJun Project Kick-off DOE Final Report Metall. & Mech. Testing Process Testing Metall. & Mech. Testing

6. Part - II

7. 7  Test specimens were taken from the center saddles on the underside of the block as indicated in the figure. Three specimens were taken from each saddle with two specimens coming from the edges of one side of the saddle and one specimen from the center of the opposite side. Sampling

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11. 11 FORD SPEC. 175 MPa

12. 12 FORD SPEC. 170 MPa

13. 13 FORD SPEC. 0.5 %

14.  It is hard to relate mechanical properties with % area porosity  It does not mean that porosity does not effect mechanical properties. Efforts should be continued to minimize porosity.  DAS seems to be a better indicator of mechanical properties  Future efforts should be directed towards improving DAS 14

15. Part - III

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17. 17 ElementNorm. wt. % 384 Spec. wt. % Al78.7277-86 Si13.1310.5 – 12 Cu3.323-4.5 Zn1.433 Fe0.861.3 Mn0.210.5 Ni0.130.5 Mg0.650.1 Sntrace0.35 Othersremainder Iron rich β phase Cu rich zones Si Needles

18. 18 Dimpled Fracture Surface Micro porosity Large Pore Crack

19. 19 Inclusion

20. Element% wt. C5.5 O0.6 Al 56.6 Si 18.4 Cl 0.1 Mn 1.2 Fe 3.2 Cu 7.1 Zn 5.6 20 Limited Ductility (Dimples) Cleavage fracture

21. 21 Limited Ductility (Dimples) Transgranular brittle fracture of Fe rich β phase Cleavage fracture

22.  The EDX and SEM gave us a better picture of the microstructure of the die castings  Plate-like Fe rich β phase is known to act as obstruction to liquid metal flow  Cu rich “sludge” is known to act as porosity initiation sites  Fracture surface was in general “Cleavage” (brittle) with limited indications of ductility  Large pores acted as crack initiation sites during tensile tests 22

23. Part - IV

24. Un-cooled core 38406Cooled core 38407 24 1.Two engine blocks, one with a cooled core and other with an un- cooled core 2.5 journals from each engine block 3.Journal 3 was sent sliced in the middle for measuring DAS across the face 4.Journals 1,2,4,5 were cut further to extract 2 tensile samples from each journal

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26.  Measurements starting from edge of hole (cooling core) every 1.5 mm till 15 mm (11 measurements). Then measurements every 3 mm till the right sectioned edge 12 mm (4 measurements) 26

27. y = mx +c DAS = 0.5 x + 18 Initial Value 27

28.  Measurements starting from edge of hole (cooling core) every 1.5 mm till 13.5 mm (10 measurements). 28

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30.  10 Measurements starting from edge of hole (cooling core) every 1.1 mm till 10 mm.  2 Measurements every 2.2 mm for 4.4 mm.  3 measurements every 1.1 mm starting from the bottom journal edge for 3.3 mm 30

31. 31 Note: Cooling is not a 1 Dimensional Problem The cooling effect measured in terms of DAS is a 3 D problem, with heat transfer taking place in all 3 directions Solidification starts both at the core and journal ends, giving the minimum DAS Journal side Core side

32. 32 COREEXTERNAL EDGE

33. 33 CORE EXTERNAL EDGE

34. UN COOLED CORE COOLED CORE 34

35. 35 B034: Cooled, No TiBor, Short Dwell, Quench E B040: Un-Cooled, TiBor, Long Dwell, Quench W

36. Hyundai- I-4 38407 cooled core Wt: 22.7 kg

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38. 38 H13 Anvilloy 3C CuBe Toolox 44

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42. Part - V

43. VC CoolingDwellTiBorQuench OnShortNoE OffLongYesW OffShortNoW OnLongNoE OffShortYesW OffLongNoE OnLongYesE OnShortYesW 43

44. VC CoolingDwellTiBorQuench B034OnShortNoE B040OffLongYesW 44

45. ID- 304 Tensile (MPa) Yield (MPa) % Elong. J1-F2652091.2 J1-R2712120.9 J2-F2642141.2 J2-R2832181.3 J4-F2652030.9 J4-R2732041.4 J5-F2352111.4 J5-R2892061.2 Ave2682101.2 Spec200150- 45 ID- 040 Tensile (MPa) Yield (MPa) % Elong. J1-F2492101.1 J1-R2812101.4 J2-F2622091.3 J2-R2621991.1 J4-F2422331.4 J4-R2562121.4 J5-F2522291.4 J5-R202-0.5 Ave2512151.2 Spec200150- B034: Cooled, No TiBor, Short Dwell, Quench E B040: Un-Cooled, TiBor, Long Dwell, Quench W

46.  The water cooled core reduces DAS and improves mechanical properties, however the cooling effect fades with increasing distance from the core  Higher cooling rates and deeper penetration can be achieved by using cores made of higher thermal conductivity alloys and/or higher flow rates  The grain refined engine block with no-cooling exhibited a fine DAS and improved mechanical properties  From our previous presentations, DAS can effectively be used as a predictor of Mechanical properties (Strong dependence: UTS & Elongation, Weak dependence: YS)  % Pore area is not a reliable predictor of mechanical properties due to the probabilistic and random nature of porosity at the section under observation 46

47. 1. Continue with DOE analysis 2. Report Writing 47

48. Thank You Questions ? 48