Additive Manufacturing amc.ati.org
Traditional Tooling 356-T6 lever casting for DSCR Wood pattern on matchboard
Additive Manufacturing (AM) A new term but the technology is almost three decades old Formerly known as Rapid Prototyping (RP) Or, known as Rapid Tooling or Rapid Manufacturing when used for casting since it s the tool (not the part itself) for making castings Build objects layer by layer from a range of materials 3
A Walk Down Memory Lane 4
Then and Now 5
Some Things Never Change And Some Do 6
Foundries were early adopters of technology Casting tooling time and money investment is reduced, enabling long-term savings from casting geometry to enter market upfront LOM was a natural fit AM for Castings 7
Changing the World AM for tooling is advantageous because it does not require a waiver or deviation from the TDP as the manufactured casting is still produced to the drawing 8
What Does AM Hold for Manufacturing? Challenges: lack of industry standards, lack of performance data (z direction properties), tapping into the AM supply chain Opportunities: short runs that require complex tooling that is no longer available, on-demand manufacturing (less stock on-hand) For casting, more of the same with improvements in build size, reduced build time, lower cost and more materials 9
Additive Manufacturing Formerly called Rapid Prototyping AM (3D printing) is a process of making three dimensional solid objects from a digital file. The 3D printed object is achieved using additive processes. The object is created by laying down successive layers of material until the entire object is built. Each layer is a thin sliced horizontal cross section of the eventual object. The design must first be created as a CAD model file using 3D modeling or scanning software.
American Society for Testing and Materials (ASTM) in 2010 created ASTM F42 Additive Manufacturing specification. A set of standards was developed that classify the Additive Manufacturing processes into 7 categories of Terminology for Additive Manufacturing Technologies. These seven processes are: 1. Vat Photopolymerization 2. Material Jetting 3. Binder Jetting 4. Material Extrusion 5. Powder Bed Fusion 6. Sheet Lamination 7. Directed Energy Deposition
What is Needed for AM Process 3D CAD solid files STL files Accuracy requirements - dimensional tolerances Material Product volume Lead time Critical features Solidification analysis is important when AM is used for tooling
Solid Works Assembly
Stereolithography (SLA) Very high-end technology utilizing laser technology to cure layer-upon-layer of photopolymer resin (polymer that changes properties when exposed to light).
Stereolithography (SLA) Processes SLA: a light and heat sensitive polymer based RP process Advantages High resolution, good dimensional accuracy, good surface finish, wide application, large build envelope, easy assembly for larger parts Disadvantages Support structure required, post-curing, liquid materials Common applications
Vat Photopolymerization A 3D printer based on the Vat Photopolymerization method has a container filled with photopolymer resin which is then hardened with a UV light source. Cross-Sectional Illustrated View - SLA Build Process
SLA Part Building
SLA Platform Draining
SLA Platform In UV Oven
SLA with Body Work
QuickCast Patterns
SLA QuickCast Pattern Assembly
Multi-Jet Modeling (MJM) Multi-Jet Modeling is similar to an inkjet printer in that a head, capable of shuttling back and forth (3 dimensions - x, y, z), incorporates hundreds of small jets to apply a layer of thermopolymer material, layer-by-layer.
Build is applied layer-by-layer to a build platform, making a 3D object then hardened by UV light
Binder Jetting Binder jetting combines two materials: powder base material and a liquid binder. In the build chamber, powder is spread in equal layers and binder is applied through jet nozzles that bond the powder particles in the shape of a programmed 3D object. The finished object is bound together by unbound material that remains in the container with the powder base material. After the print is finished, the remaining powder is cleaned off and used for printing the next object.
Material Extrusion The most commonly used technology in this process is Fused Deposition Modeling (FDM). Technology works by using a plastic filament or metal wire which is unwound from a coil which supplies material to an extrusion nozzle.
Fused Deposition Modeling (FDM) Process involving use of thermoplastic materials (polymer that changes to a liquid upon the application of heat and solidifies to a solid when cooled) injected through indexing nozzles onto a platform. The nozzles trace the cross-section pattern for each particular layer with the thermoplastic material hardening prior to the application of the next layer. The process repeats until the build or model is completed. Specialized materials may be needed to add support to some model features. Similar to SLA, the models can be machined or used as patterns.
FDM Process )
FDM Printed Part
Powder Bed Fusion Selective Laser Sintering (SLS) This technology uses a high power laser to fuse small particles of plastic, metal, ceramic or glass powders into a mass that has the desired 3D shape. The laser selectively fuses the powdered material by scanning the cross-sections (or layers) generated by the 3D modeling program on the surface of a powder bed. After each cross-section is scanned, the powder bed is lowered by one layer thickness. Then a new layer of material is applied on top and the process is repeated until the object is completed.
Selective Laser Sintering Process
SLS Part
SLS Part
Removing Part from Unbound Powder
SLS Printed Powder Metal Parts
Printed Metal Parts
GE Leap Engine Printed Metal Nozzle, 20 Per Engine Required
The 3D printed fuel nozzle will guide fuel into the LEAP engine s combustion chamber
3D Laser Sintered Printed T25 Sensor Enclosure Unit Produced by GE Aviation and Certified by FAA
Direct Metal Deposition (DMD) Printed Metal Manifold
HIPping for Metal Improvement
Direct Metal Parts & Mold Inserts
Die Casting Inserts Printed Insert Exterior Internal Cooling Passages
Sheet Lamination Sheet lamination uses material in sheets which are bound together with external force. Sheets can be metal, paper, or a form of polymer. Metal sheets are welded together by ultrasonic welding in layers and then CNC milled into a proper shape. Paper sheets can be used also, but they are glued by adhesive glue and cut in shape by precise blades.
Laminated Object Manufacturing (LOM) How the process works Paper sheet based laser profile cutting Advantages Wood-like, hard No support required Disadvantages Delamination is possible Not good for small and thin wall features (<.2 in size or < 0.1 in thickness) poor accuracy Common applications
LOM
Simplified Model of Ultrasonic Sheet Metal 3D Printing
Sheet Metal Printer Using Fabrisonic AM Paired with CNC Milling Machine
Directed Energy Deposition This process is mostly used in the high-tech metal industry and in rapid manufacturing applications. The 3D printing apparatus is usually attached to a multi-axis robotic arm and consists of a nozzle that deposits metal powder or wire on a surface and an energy source (laser, electron beam or plasma arc) that melts it, forming a solid object.
Direct Energy Deposition with Metal Powder and Laser Melting
Direct Energy Deposition (DED) Process
Direct Energy Deposition Metal Part
CNC Machined Tooling Sand tooling: cut pattern and core boxes from urethane tooling board Investment tooling: cut directly into aluminum plate stock Rubber plaster tooling: machine master pattern from urethane tooling board Die casting: machine mold inserts directly from solid model file
Starting Ren Board Pattern
Completed Ren Board Pattern
Ren Board Core Box
Concept Models for Eurostar Telecommunications Satellite
Final Design Printed in Aluminum Alloy
Technical Data Package (TDP) Using AM for any of the casting processes requires NO CHANGES to the current TDP
Sand Castings Using AM Available processes: Printed sand molds and cores Convention patterns with AM cores AM patterns and core boxes Hybrid combination of above
Sand Castings Using AM Process steps: CAD model of casting including machine stock and draft as required by chosen process Mold design similar to standard molding process, draft and core prints for core set Model mold with gating design, chills etc. Hybrid may be combination of above
General Casting Process
Sand Casting and Additive Manufacturing
FDM Polycarbonate Matchplate Insert Pattern Defense Application A356.0 Aluminum Sand Casting
Green Sand Process
Dry Sand Process
Casting Production
What Kind of Casting Methods Are Available for AM? Investment Casting Sand Casting Plaster Casting Die Casting Permanent Mold Casting
Printed Sand Molds and Cores
SLS Gear Box Core Assembly & Casting
SLS Core Assembly
Sand Cores and Molds
Intake Manifold AM Sand Mold and Aluminum Casting
Aluminum Sand Casting
Printed Core Assembly in Printed Mold
Stator Casting: Two Required
Printed Sand Mold and Core
Machined Casting from Printed Mold
Hybrid Sand Casting Tooling Cope impeller pattern CNC machined tooling board
Drag Impeller Pattern CNC Machined Tooling Board
Printed Sand Impeller Core Top
Printed Sand Impeller Core Bottom
Size is Typically Not a Concern
Deep Vanes Are Not an Issue
Aluminum Cast Pump Body AM printed mold and 1 piece internal core
Steps Required for Using AM to Produce Legacy Castings or Parts Create CAD model from 2D drawing Decide best process for requirement AM tooling less casting Complete AM pattern tooling Hybrid tooling Standard production tooling
Part Drawing
STL Solid Model
SLA Pattern
2-on Plastic Pattern for Sand Casting
Aluminum Casting
Ductile Iron Valve sand casting with printed sand core for internal passages. Exterior produced with standard sand pattern equipment. External view of casting
Internal View of Casting
Internal Passages
Printed 1 piece Internal Sand Passage Core
Original OEM Knuckle
CAD Model of Machined Casting
Printed Master Pattern for Cast Match plate
Printed Model of Machined Casting for Fit Check
Sand Casting Pattern Plates
Finished Machined Casting
Investment Castings Process steps CAD model Tooling wax mold or AM patterns Rig patterns / gating Shell dip coat Fire shell Pour metal Shake out, grind, and clean casting Heat treat NDT etc.
Typical Aluminum Investment Wax Die
Stainless Steel Check Valve Body Original Design - Investment Casting Wax Pattern - Utilizing a soluble core AM can print wax pattern and soluble core simultaneously
Preformed Ceramic Cores Stock and custom core manufacturing processes Extruded, molded, custom ground and machined
Bronze Impeller Wax Pattern - utilizing preformed ceramic core AM can print ceramic core Actual resulting casting
Printed Ceramic Cores
Bronze Impeller Wax Pattern - utilizing AM printed ceramic core Resulting stainless steel casting
Printed Ceramic Shell and Cores
Printed Ceramic Core
Cast Inconel Turbine Blade Produced Without Tooling
27 diameter x 9 high impeller, investment casting weight 505 lbs, material 17-4 PH SS Reverse engineered from existing part as no drawings or models were available. Once the reverse engineered model was complete and approved, it took 6 weeks to complete SLA pattern, produce ceramic mold, cast, finish, heat treat, inspect, machine and ship finished casting.
Process Steps for Investment Casting Impeller SLA QuickCast Pattern
Ceramic Dip Coats
Pouring Metal Casting
Heat Treated Casting
Finish Machined Casting
Summary Only 4 castings needed for spare parts order Production tooling cost approx $50,000, lead time 16 weeks SLA cost $5,500 each Casting cost using SLA is approx 10% higher than using production wax pattern. Using AM saved 26 weeks in lead time and $48,000 in cost savings on four parts.
54 Lb. 17-4 PH STAINLESS STEEL INVESTMENT CAST HOUSING Produced 6 sample castings using SLA Quick Cast disposable patterns to prove out design. 75 production castings produced from Aluminum investment tooling.
CAD Model, SLA Quick Cast Pattern, Aluminum Investment Casting
Benet Army Laboratory Deflector Tray Original Fabricated Design Carbon Steel
Army s XM360 Cannon being redeveloped into the XM360E1 for the next M1 Abrams tank upgrade
Snapshot of CAD Model Casting Design Converted to 17-4 PH
2D Drawing of Casting Requirements
Added Tie Bars to CAD Model
SLA QuickCast Pattern with Tie Bars Added
CAD Model of Gating Design
CAD Model of Tool Point Straightening Inspection Fixture
Printed Straightening Fixture
Casting was HIPped Prior to Heat Treat and Straightening Straightening fixture used with go/no-go gauge points
17-4 Casting Side View
Casting Front View, 0.08 Wall Thickness
Successes Met the 20 lb weight bogie at 19 lbs 20% cost savings over fabrication Anticipated reduced scrap rate over 50% X-ray grade B critical areas balance grade C Prototype delivered 110 days ARO
Cannon Goes Light With Steel Alloy Steel s high yield strength and tolerance of deflection without damage helped keep the weight low in a 15-piece fabrication to casting conversion Gary Burrow, HA Burrow Pattern Works Inc., Silesia, Montana
Model Produced from 2D Drawing 5 Spare Parts Required for DLA
A357 T6 Aluminum Castings Produced from SLA QuickCast Patterns Investment Cast, 0.08 Wall Thickness
Passenger Aircraft Seat Frames Converted from Machined Billet to Magnesium Investment Casting Source: Wetzel, Shannon. Casting of the Year: Aerospace Seatback Frame by Aristo-Cast. Modern Casting. May 2017: 24-27. Print.
Magnesium Investment Cast Seat Frame Direct from AM Printed Pattern Honeycomb design in width and thickness Impossible to build tooling for such a design
Passenger Seat Frame Projected Savings Weight of 1.7 lbs reduced by approx 350% Airbus A321 Fuel savings: $12,935/year 25 year service life savings: $323,375 Airbus A380 Fuel savings: $103,324/year 25 year service life savings: over $2M
Rubber Plaster Process Castings Printed Master Pattern and Casting
Fixtures Casting straightening fixtures Casting check fixtures Machining fixtures Assembly fixtures Bonding fixtures Gauges (go/no-go) fit check
Machining Holding Fixture
Print Multi-Shore Hardness Materials at the Same Time
Multi-Material Printing
Go/No-Go Gauges
Press Fit Assembly Fixture
Advancements More and improved materials Lower costs (equipment and materials) Improved accuracy Increase speed of printing Improved or no support requirements
Conclusions Using AM for castings can be very cost effective AM can be used for direct casting or tooling No changes to TDP required Quantity must be considered when deciding process (direct casting or tooling) Time to delivery - emergency buy or stock item AM support tooling can be cost effective and speed up delivery time To obtain the advantages of AM, solid models are required
Questions and Answers amc.ati.org
Acknowledgements AMC s Casting Solutions for Readiness program is sponsored by the Defense Supply Center Philadelphia, Philadelphia, PA and Defense Logistics Agency, Ft. Belvoir, VA 172