QuickCast Direct Patterns for Investment Casting

Transcription

1 QuickCast Direct Patterns for Investment Casting Tom Mueller Founder and Partner, Express Pattern Vernon Hills, IL IL

2 Agenda About Express Pattern An Overview of Direct Patterns The Four Primary Uses of Direct Patterns A New Resin for QuickCast Patterns Case Studies

3 About Express Pattern Founded in 1999 Focused on investment casting applications of rapid prototyping Currently using stereolithography and thermojet technologies Largest provider of direct patterns

4 SLA Capability 12 SLA Systems 1 SLA Viper Pro 3 SLA SLA SLA SLA SLA Viper 2 SLA 250

5 Viper Pro Largest SLA format 30x26x22 build envelope

6 Thermojet Capability 9 Thermojet Systems

7 New Foundry Guide Covers all aspects of using QuickCast patterns in investment casting Available at no charge to investment foundries

8 An Overview of Direct Patterns Definition Direct Pattern Methods Important Pattern Considerations Comparison of Leading Direct Pattern Methods

9 Definition Investment casting patterns made without using tooling Generally made with rapid prototyping methods Not just for prototypes Approximately 60,000 direct patterns were cast last year ~40% used for production castings

10 Creating Direct Patterns Scale Factor CAD Model STL File Additive Fabrication System Direct Pattern

11 Types of Direct Patterns Stereolithography (SLA) QuickCast Patterns Thermojet Patterns Selective Laser Sintering (SLS) Castform Patterns Solidscape Patterns Laminated Object Manufacturing (LOM) Patterns Fused Deposition Modeling (FDM) Patterns Z Corporation Patterns Machined Wax Patterns Wood Patterns

12 Types of Direct Patterns Stereolithography (SLA) QuickCast Patterns Thermojet Patterns Selective Laser Sintering (SLS) Castform Patterns Solidscape Patterns

13 SLA QuickCast Patterns

14 Honeycomb Internal Structure Hollow structure with hexagonal supports Allows stucture to completely drain Pattern can collapse inward as it expands with heat Less mass to burn out

15 QuickCast Advantages Accurate Good Surface Finish Lightweight Disadvantages Leak Possibility De-Wax Process

16 Thermojet Patterns

17 Thermojet Advantages Wax Pattern Good Surface Finish Disadvantages Accuracy Pattern Strength

18 SLS Castform Patterns

19 Castform Advantages Pattern Strength Disadvantages Accuracy Surface Finish Limitations De-Wax Process

20 Solidscape Patterns

21 Solidscape Advantages Accurate Detail Resolution Wax Pattern Disadvantages Slow

22 Important Pattern Considerations Build Process Considerations Accuracy Surface Finish Build Envelope Build Speed Material Considerations Ability to Assemble Pattern Strength Ease of Processing Residual Ash Heavy Metal Content

23 Accuracy Very little good data on RP accuracy exists Express Pattern has done the largest accuracy study ever done Based on >15,000 measurements

24 QuickCast and Thermojet Pattern Accuracy: Probability of a Dimension being within a Specified Tolerance Probability of a Dimension Being within a Specified Tolerance 100% 80% Probability 60% 40% 20% 0% QuickCast Patterns Tolerance (inches) Thermojet Patterns

25 Other Accuracy Conclusions Accuracy not dependent on: Dimension type Build direction

26 Process Comparison Chart QuickCast Thermojet CastForm Solidscape Accuracy Good Med - Poor Med Very Good Surface Finish Good Med-Good Med Good Build Envelope 25x30x22 10x7.5x8 22x22x30 6x6x12 Build Speed Medium Medium - Slow Medium Slow Pattern Strength Good Medium Very Good Medium Ease of DeWax Medium Very Good Medium Very Good Ability to Assemble Good Medium Good Good Residual Ash Good Very Good Medium Very Good Heavy Metal Content Good-Very Good Very Good Very Good Very Good

27 Direct Pattern Applications Prototype Castings Process Development Initial Production Castings Low Volume Production

28 What are Prototype Castings? Castings provided to the customer for purposes of testing and verifying the design prior to production Usually ordered prior to beginning tooling

29 Typical Casting Development Process Production Yes Complete Design Procure Tooling Create Casting Test OK? No Revise Tooling Revise Design

30 Costs of Design Changes Tooling rework costs Tooling rework time Delayed Product Introduction Restrictions on design changes

31 Effect of Design Changes Effect of Design Changes QuickCast Castings Time for Tool Rework Time Conventional Castings Difference in Time for Corrected Design Tooling Lead Time Design Change Number of Patterns

32 Benefits of Prototype Castings Verify design before investing in tooling Reduced risk of tooling rework charges Reduced risk of product delays due to tooling rework Greater design freedom in making design changes

33 Part 2: Direct Pattern Applications Prototype Castings Process Development Initial Production Castings Low Volume Production

34 How can Direct Patterns Assist in Process Development? Some steps of the casting process cannot be optimized until patterns are available Direct patterns can be used instead of waiting for molded patterns

35 Process Development Steps that Require Patterns Delay Delivery Possible Tool Rework Gating Trials Tree Assembly Optimization Final Shrink Determination Robotic Dip Programming Straightening Fixtures

36 Solution Use Direct Patterns to develop process before tooling is delivered Initial concentration on areas that could result in tooling changes

37 Benefits of Using Direct Patterns in Process Development Reduced risk of late delivery Reduced Risk of incurring time and cost of tooling rework

38 Part 2: Direct Pattern Applications Prototype Castings Process Development Initial Production Castings Low Volume Production

39 Initial Production Castings Use direct patterns to create initial production castings while tool is in process Allows delivery of low volumes of production castings much faster than would be possible with molded patterns Ramp up to normal production delivery when tool is delivered

40 Time to Deliver Castings Time to Deliver Castings Molded Wax Pattern Castings Delivery Time Time QuickCast Castings Tooling Lead Time Number of Castings Castings shipped before tooling delivered

41 Benefits of Using Direct Patterns for Initial Production Castings available much earlier than possible with molded patterns alone Possible to catch design problems

42 Direct Pattern Applications Prototype Castings Process Development Initial Production Castings Low Volume Production

43 Low Volume Production Castings Using Direct Patterns instead of molded wax patterns for low volume production runs.

44 Total Cost of Castings Total Cost of Castings QuickCast Castings Conventional Castings Machined Parts Total Cost of Parts New Business Direct Instead of Molded Conventional Casting Cost of Tooling Cost Break-Even Qty. Number of Parts QuickCast Cheaper Wax Cheaper

45 Time to Deliver Castings Time to Deliver Castings Conventional Castings Delivery Time Time QuickCast Castings Tooling Lead Time Time Break-Even Qty. Number of Castings QuickCast Faster Wax Faster

46 Effect of Design Changes Effect of Design Changes Cost of Tool Changes Conventional Castings Total Cost of Castings New Cost Break Even Quantity QuickCast Castings Cost of Tooling Design Change Cost Break-Even Qty. Number of Castings

47 Effect of Design Changes Effect of Design Changes QuickCast Castings Time for Tool Rework Time Conventional Castings Difference in Time for Corrected Design New Time Break Even Quantity Design Change Time Break-Even Qty. Number of Patterns

48 Benefits For low volumes, direct patterns can save both time and money compared to molded wax patterns and machining Very low penalty for design changes

49 New SLA Resin for Investment Casting Primary resin for QuickCast patterns has been WaterShed from DSM Somos Last year, DSM introduced ProtoCast AF Express Pattern beta tested and evaluated

50 Residual Ash Ash remaining after burnout as a percentage of the original pattern weight Can cause problems with the casting Surface pitting Inclusions Usually must be cleaned out of the shell

51 Residual Ash Testing Measured at two combustion temperatures 1500ºF below cristobalite conversion temp 1800ºF above cristobalite conversion temp Measured at 6 burn times 30,60,90,120,150 and 180 minutes

52 Residual Ash at 1500F Combustion Ash Content at 816 C (1500 F) Ash Content (%) ProtoCast WaterShed Ashing Time (minute)

53 Residual Ash at 1500ºF Combustion Percent % 0.013%

54 Residual Ash at 1800F Combustion Ash Content at 982 C (1800 F) ProtoCast WaterShed Ash Content (%) Ashing Time (minute)

55 Residual Ash at 1800ºF Combustion 0.09 Percent % 0.015%

56 Foundry Test Two Assemblies One assembly with 4 nine-wall parts built with WaterShed resin One assembly with 4 nine-wall parts built with ProtoCast AF resin Shells built at the same time Fired at the same time in the same furnace

57 Foundry Test

58 Foundry Results WaterShed ProtoCast AF

59 Results Ranked by Importance Resid. Ash 1500ºF Resid. Ash 1800ºF DSM Somos Watershed 0.093% 0.089% DSM Somos ProtoCast AF.013% 0.015% 86% Reduction! 83% Reduction!

60 Results Ranked by Importance Resid. Ash 1500ºF Resid. Ash 1800ºF DSM Somos Watershed 0.093% 0.089% DSM Somos ProtoCast AF.013% 0.015% Antimony Free? No Yes 86% Reduction! 83% Reduction! 100% Reduction!

61 Thermal Expansion Why is it important? Thermal expansion is the cause of cracking in the autoclave

62 Coefficient of Thermal Expansion CTE

63 9 Wall Test Part Casting Casting

64 Results Ranked by Importance Resid. Ash 1500ºF Resid. Ash 1800ºF CTE µmm/mm-ºc DSM Somos Watershed 0.093% 0.089% DSM Somos ProtoCast AF.013% 0.015% Antimony Free? No Yes % Reduction! 83% Reduction! 100% Reduction! 19-31% Reduction!

65 Case Studies Spacecraft Electronics Housing Deep See Diving Helmet Control Handle Aircraft Gimbal Camera Mount Automotive Bracket Fighter Air Inlet Scoop for Electronics Cooling Exhaust Manifold

66 Messenger Space Exploration Vehicle Multiyear mission to Mercury Launched March 2004 Venus Fly-bys June 2004 and March 2006 Mercury orbit April 2009

67 Messenger Electronics Housing Casting by NuCast, Londerry,, NH QuickCast pattern Aluminum 356 Only minor machining required

68 Messenger Electronics Housing

69 Kirby Morgan Dive Helmet Stainless Steel Deep Sea Dive Helmet Cast by AristoCast, Almont, MI QuickCast Pattern Won AFS Best in Class Casting Award 2006

70 Dive Helmet Pattern

71 Pouring the Helmet

72 Cooling and Cleanup

73 Finished Casting

74 Assembled Helmet

75 Control Handle Aircraft control handle Cast by UniCast, Londonderry, NH Prototype and initial production castings delivered using QuickCast patterns

76 Aircraft Camera Gimbal Mount Gimbal Mount for Reconnaissance Camera Nu-Cast, Londonderry, NH

77 Aircraft Camera Gimbal Mount Foundry Material Dimensions Weight Lead Time Nu-Cast Londonderry, NH Aluminum 14 x14 x14 17 pounds 3 Weeks Tool Cost $85,000 Tool Lead Time Cost Break Even Time Break Even Weeks 32 Castings 87 Castings

78 Automotive Casting Foundry Material Dimensions Weight Aristocast Almont, MI, USA Aluminum 9.5 x16 x6.5 4 pounds Tool Cost $37,000 Tool Lead Time Cost Break Even Time Break Even 6-8 Weeks 40 Castings 111 Castings

79 Fighter Air Inlet Scoop Inlet Scoop to provide air to cool electronics Uni-Cast, Londonderry, NH Provided initial castings 3 months prior to delivery of production tooling Winner of 2005 ICI Casting Award

80 Rapid Prototype Wax Patterns

81 Rapid Prototype Cast Parts

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86 Thank You