3D Printing Materials

Additive Manufacturing Material

Additive Manufacturing or additive layer manufacturing is used to create durable and lightweight parts. Additive manufacturing uses Computer-Aided-Design (CAD) or a 3D model to direct hardware how to build an object in successive layers. The CAD drawing provides a set of instructions or blueprints, illustrating all the intricacies of the product being manufactured. These blueprints instruct the machine where and when to place the material. Complex objects can be produced in this manner without the need to join together separate parts. This eliminates post-processing labor and can reduce overall cost. Some examples of products made using additive manufacturing technologies include surgical implants, parts for aerospace and defense industries, automotive parts, and rapid prototypes. Additive manufacturing is used by vastly different industries. The wide variety of materials available in additive manufacturing allows designers to easily create industry-specific products and parts.

Polymers, metals, and ceramics are the three primary types of materials that can be used for additive manufacturing. These materials are commonly available in powder or wire feedstock. Additional materials include paper, adhesive paper, chocolates/food, and polymer/adhesive sheets for Laminated Object Manufacturing. It is possible to print nearly any material using the additive manufacturing method of layering. However, the process can alter the microstructure of the material due to the high heat and pressure used during additive manufacturing. The chosen material can also affect the finish. Material characteristics may not be the same during pre-manufacture as they are post-manufacture.

Polymers

Polymers are common plastics like Acrylonitrile Butadiene Styrene (ABS) and Polycarbonate. This category also contains waxes, epoxy-based resins, and structural polymers. Polymers become soft when heated but will regain firmness after cooling. Polymer powders can be mixed with other polymers or materials to create alloys that have different structural and aesthetic properties. Polymers used in additive manufacturing include / /

• ABS
• Polylactide (PLA) and soft PLA
• Polycarbonate (PC)
• Polyamide (Nylon)
• Nylon 12 (Tensile strength 45 MPA)
• Epoxy Resin
• Wax
• Photopolymer Resins

Metals

Different metals can be used for additive manufacturing. Metal for additive manufacturing begins as either powder or filament. Parts made from metal retain superior mechanical properties. Metals used in additive manufacturing include / /

• Aluminum Alloys
• Cobalt-Based Alloys
• Tool Steels
• Nickel-Based Alloys
• Stainless Steels
• Titanium Alloys
• Precious Metals (gold, silver)
• Copper Alloys

Additive Manufacturing Parts and Images

Additive Manufacturing Materials by Technology

Fathom offers a wide variety of materials for additive manufacturing. Selecting the best medium for your unique part is critical to producing a viable product. Fathom offers six additive manufacturing technologies with a diverse range of material options.

PolyJet Materials

PolyJet technology is capable of creating smooth surfaces, thin walls, and complex geometries all while holding tolerances within 0.1 mm. PolyJet is the only technology that supports a wide selection of materials with properties that range from rubber to rigid and transparent to opaque. PolyJet can also 3D print with multiple materials in a single build. This allows designers to achieve combinations of colors and characteristics without secondary processing. Parts requiring a hard shell and soft grips can be made in one shot and be put directly to use.

How does PolyJet technology work? PolyJet is a photopolymer-based jet printing process that distributes material droplets, layer-by-layer, onto a build platform. Each layer is immediately cured with a flash of UV light. The object is fully cured and can be handled immediately without post-curing at the end of the build process. PolyJet technology utilizes a water-soluble gel as a support material. The gel material is designed to provide support for complex geometries during the printing process but can easily be removed after manufacturing. The gel dissolves in water or can be water jetted for faster removal.

PolyJet 3D Printed Parts and Images

Stereolithography Material

Stereolithography (SLA) technology is ideal for larger parts that need high-resolution finishes. It is an extremely cost-effective solution for creating durable, aesthetically pleasing medium- or large-sized items on a tight deadline. SLA resins are available with extremely high heat deflection. These materials are an excellent choice for building molds or inserts.

How does the SLA technology work? Like PolyJet, SLA uses photopolymer resins that are cured with an ultraviolet laser. The UV laser traces a shape dictated by the original file across the surface of the resin bath. The resin touched by the laser hardens, then the build platform descends in the resin bath, and the next layer is added. This process is repeated until the entire part is complete.

SLA offers a combination of high-quality resolution and surface finishes for large pieces. SLA is also very effective at faithfully capturing the intricacies of even the most complex parts. Clear 3D printed SLA resins can achieve colorless clarity with additional post processing to mimic clear plastics. SLA specializes in creating parts that may be very cost-intensive to produce using any other method of manufacturing. Parts made with SLA are consistently used for trade show models, aesthetic parts, and snap fits/functional assemblies.

SLA 3D Printed Parts and Images 

Fused Deposition Modeling Materials

Fused Deposition Modeling (FDM) technology is ideal for building concept models, functional prototypes, and end-use parts using standard, engineering-grade, and high-performance thermoplastics. The FDM process uses the same types of raw materials used in the injection molding process. This gives FDM a distinct advantage over other additive manufacturing technologies by allowing designers and engineers the chance to work with a finished product before going into mass production.

How does FDM technology work? FDM is a filament-based additive technology with a moving print head that extrudes a heated, thermoplastic material in a pattern, layer-by-layer, onto a build platform. This technology includes the use of support material to create supportive structures that are removed by force or dissolved in solution.

The FDM technology was invented 30 years ago by Stratasys founder Scott Crump. The FDM process uses the same production-grade thermoplastics found in traditional manufacturing processes. FDM is ideal for applications that require tight tolerances, extreme toughness, and environmental stability. Material options include specialized properties like electrostatic dissipation, translucence, biocompatibility, VO flammability, or FST ratings.

FDM 3D Printed Parts and Images

Selective Laser Sintering Material

Selective Laser Sintering (SLS) technology is a powder-based additive technology used to create models, prototypes, and end-use parts in durable, engineering-grade thermoplastics. SLS technology should be considered for applications that involve high-complexity, organic geometries, and extreme durability. SLS is ideal for short-run production and prototyping. The technology is also capable of producing parts with finer details than most processes when using high-strength plastics. SLS material composition is among the most robust available from additive manufacturing.

How does SLS technology work?

SLS uses a blade to spread a thin layer of powder over the build platform. A laser then shoots a cross-section of the part, fusing the powder together. The build platform then drops one layer and the process begins again until the part is finished. Parts are then excavated out of the build powder-cake and bead blasted to remove loose material. The unused powder in the build envelope acts as the support structures. Unused powder can also be reclaimed and used for the next project.

SLS 3D Printed Parts and Images

Multi Jet Fusion Material

Multi Jet Fusion (MJF) technology is quickly becoming a popular choice for 3D printing prototypes and production parts. MJF can be used for enclosures, electronics housings, complex ducts, lattice structures, and functional assemblies. The technology is capable of 3D printing parts with high detail and durability. MJF is ideal for short production runs as the process allows for nesting in the Z-direction. To learn more about MJF, read a featured FAQ blog post by a Fathom Applications Engineer.

How does MJF technology work?

MJF builds parts by laying down a thin layer of powder on a print bed. The inkjet array in the print carriage sweeps over the print bed, jetting two agents into the powder — a fusing agent, printed where the powder will fuse together, and a detailing agent that is used to reduce fusing at the part boundary. The detailing agent enables MJF parts to achieve a high level of detail not possible with other additive manufacturing technologies.

Nylon 12 is a thermoplastic that is strong enough for functional, small- to medium-sized prototypes and production parts. It is an ideal material for complex assemblies, housings, enclosures, and watertight applications. Nylon 12 will produce smooth surfaces and fine details. It provides excellent chemical resistance to oils, greases, aliphatic hydrocarbons, and alkalis. Parts produced are a non-uniform light gray but can be dyed a darker color for a uniform appearance.

MJF is similar to Selective Laser Sintering. Both processes use a powder bed. SLS uses a laser to fuse the powder while MJF is a chemical process using a fusing agent.

Direct Metal Laser Sintering (DMLS) 3D Material  

Metal 3D printing technology, also known as Direct Metal Laser Sintering (DMLS) and Direct Metal Laser Melting (DMLM) is a metal-based additive layer manufacturing technology.   

DMLS allows designers and engineers to streamline the manufacturing process with precision metal prototypes and low-volume metal production parts. These types of parts would be impractical or cost prohibitive to machine in a conventional manner. Fathom creates metal parts using a fiber laser fired onto a metal plate, repeatedly adding layers of powdered metal and fusing them to previous layers. Additional post-processing is recommended even though the resulting part is accurate, with excellent surface quality and mechanical properties, immediately after manufacturing 

How does DMLS technology work? A metal 3D printer uses a laser beam to melt layers of metal powder, 20 to 60 microns thick, on top of each other. Powdered metal is spread across the entire build platform and selectively melted to previous layers. This additive process allows metal parts to be grown out of a bed of powdered metal. The process is like other polymer-based 3D printers that use powder bed fusion, including Selective Laser Sintering and Multi Jet Fusion. 

Benefits of Metal Prototypes / /

• Precision
• High-Quality
• Low-Volume
• Strength

Materials include / /

• Stainless Steel
• Maraging Steel
• Inconel
• Aluminum
• Titanium
• Other Materials Available On Demand

In-House Post-Processing / /

• Support Removal
• CNC Secondary Machining (Critical Dimension and Re-Qualification)
• Tapping, Threading, and Helicoils
• Vibratory Polishing and Surface Treatment
• Annealing and Age Hardening
• Painting and Finishing

Fathom uses EOS and SLM build platforms.

• The build volume for the SLM is 11 in. x 11 in. x 13.8 in.
• The build volume for the EOS is 9.85 in. x 9.85 in. x 8.5 in.

3D Printing Material Finishes

Parts made using additive manufacturing can have the same look, feel, and finish as a product made with traditional manufacturing processes. Any finishing that may be required depends on the kind of additive manufacturing method used. Finishing may include / /

• Support Removal / / This may be done with a water jet, removing the support by hand, a chemical bath, or digging. Support removal varies by the technology used.
• Sanding / / The part may need to be sanded by hand or mechanically once the support has been removed. Sanding is necessary if there are any traces of the support structures.
• Mass finishing / / The parts are placed inside a tub filled with sanding/polishing media. The parts are tumbled inside the tub and the movement works to remove imperfections from the surface of the part. This method is not suitable for objects with delicate features. Mass finishing may be used if sanding by hand is deemed too time consuming.
• Painting / / Parts may be dyed or painted. Some parts may be sprayed with a specialty paint that gives the object a different texture. Painting is necessary when a designer would like to change the color or texture of a part.
• Electroplating / / The part is immersed in a solution of water and metal salts and an electrical current is passed through it. This allows metal cations to form around the part. Several layers may be applied to attain the desired thickness. Electroplating increases the strength of the part by adding an exoskeleton. The electroplating process may be used to give an object the look of a higher quality material.
• Bonding / / Bonding may include solvent bonding, super gluing, epoxies, hot air welding, or ultrasonic spot welding. Bonding is necessary when a part is printed in small pieces that must be assembled to form a larger product.
• Infiltration / / Infiltration uses an epoxy resin that is brushed onto the surface of the part. The resin sinks into the pores within the material. The part is then cured inside an oven. Infiltration adds strength, water tightness, and chemical resistance to an object. This process may be used if a 3D printed part is fragile.
• Bead blasting / / Plastic or glass beads are sprayed over a part using a blaster gun, giving the part a uniform matte finish. This is particularly useful for parts made using Selective Laser Sintering as it removes any loose powder that may be stuck to the surface. Bead blasting prepares the part for painting.

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Additional Resources

• All Fathom Capabilities
• Additive Manufacturing
• 3D Printing Services
• Metal 3D Printing
• 3D Printing Quotes
• Sheet Metal Fabrication
• Sheet Metal Prototyping
• CNC Machining
• Urethane Casting
• Injection Molding
• 3D Printing vs. Injection Molding
• ITAR Manufacturing
• Medical Device Manufacturing