3D metal printing: Cheat sheet
Advances in 3D metal printing technology that allow for micrometer-scale precision make the rapidly-maturing field compelling for a wide variety of industries. Businesses in various sectors increasingly rely on additive manufacturing technology for rapid prototyping, as well as production-ready parts and reducing warehousing overhead with just-in-time order fulfillment. Likewise, materials costs can be reduced with additive manufacturing, as the amount of waste produced is less.
TechRepublic's cheat sheet about 3D metal printing is an introduction to the additive manufacturing technology. This guide will be updated periodically as new solutions and services are announced.
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What is 3D metal printing and additive manufacturing?
Fundamentally, 3D printing is a catchall term for a wide variety of additive manufacturing technologies. The first of these technologies used photopolymers, which are heated using ultralight light in a process called stereolithography (SLA). Most consumer-oriented 3D printing solutions use inexpensive thermoplastic materials, using a technique called fused deposition modeling (FDM) or fused filament fabrication (FFF). For an overview of these concepts, see TechRepublic's 3D printing cheat sheet.
Many companies use SLA printers to create casting patterns for injection molding of metal parts. Because of the different physical properties of metals, and the differing mechanical properties of various printing methods, a variety of manufacturing processes exists for directly 3D printing metal parts.
Selective laser sintering (SLS) uses a powerful laser to bind small particles together. SLS can be used for powdered metal, as well as plastic, nylon, polystyrene, ceramic, and glass powders. SLS does not require support structures when printing, as parts are surrounded by unsintered powder during printing.
Selective laser melting (SLM) or Direct metal laser sintering (DMLS) is a process in which metal alloy powder is spread onto a print bed, and particles are fused together using an overhead laser. Electron-beam melting (EBM) is a subclass of SLM, in which powder is placed in a vacuum and fused using an electron beam. EBM has the added benefit of being usable with titanium alloys.
Directed energy deposition (DED) is a process by which metal powder is placed on a build surface by a specialized nozzle, and melted in place by a laser or electron beam mounted to the nozzle. Existing laser and electron beam welding techniques influenced this technique. This technology is often used in repairs of existing devices, as raw material can be precisely deposited and melted into place to patch damage from general wear and tear.
Laminated object manufacturing (LOM) allows for metal foil, as well as plastic film or paper, which is then layered on top of itself and cut using a knife or laser.
Binder Jetting is a technique that combines powder particles using a selectively deposited liquid binding agent. Binder Jetting does not utilize heat during the build process and does not require a build plate for stability. It is generally considered faster and more cost-effective than other 3D metal printing techniques, though these parts generally require post-processing curing or sintering, depending on the material used.
Electron beam freeform fabrication (EBF³) is a process that allows for parts to be built using a metal wire shaped and bonded using an electron beam in a zero-gravity environment. This process has not yet been commercialized, but it is being actively researched by NASA.
What are the benefits of using 3D metal printing?
Because of the additive properties of 3D metal printing, it is possible to use reclaimed or recycled materials, as 3D metal printing technologies rely on joining metal particles. Likewise, to contrast against subtractive manufacturing-in which parts are milled out of solid blocks of raw materials-the types of structures that can be created using 3D metal printing vary significantly from those used in subtractive manufacturing. For that reason, 3D metal printing is considered an ecologically friendly technology.
Using 3D metal printing, bespoke, custom metal parts can be produced inexpensively in limited production runs for specialized use cases. Likewise, as these parts can be printed on demand and closer to the engineering teams designing parts, the delays and expense involved with waiting for a commercial parcel or freight services to deliver parts from an outsourced foundry can be eliminated, speeding up development time and product launch cycles.
With the use of directed energy deposition (DED), 3D metal printers can make repairs to traditionally manufactured metal parts, particularly in heavy industrial applications where these parts are subject to degradation from use. Mending existing parts with DED can extend the service life of the devices those parts are used in, and ensures that they can be used with the structural integrity necessary to operate safely.
Which industries use 3D metal printing?
A wide variety of industries are relying on 3D metal printing to produce parts and simplify how combinations of 3D printed and traditionally manufactured parts are connected to create finished products. 3D metal printing also enables companies to print replacement parts on demand, reducing the overhead required for warehousing parts and sunk costs of unsold inventory.
Foremost among these is the aerospace industry, as significant cost savings are found by creating lighter parts to use in airplanes, and more parts can be custom produced for that purpose, rather than needing to tool designs around commercially available components. In a presentation at GE's Industry in 3D event in 2018, a helicopter engine redesigned using 3D printing enabled one part to be reduced from 400 pieces to 16, while a second was reduced from 855 pieces to 12, which resulted in a total 5 pound reduction in weight, and 80% cost reduction.
Weight reductions in the aerospace industry return dividends for customers over the lifetime of the aircraft, as lower aircraft weight results in higher fuel efficiency per trip. 3D metal printing allows for the creation of "hollow" parts with internal supports, where previously these parts would be milled from solid blocks of metal. SpaceX used 3D printed parts in engines used in rockets. Though fuel requirements are comparatively less, this also benefits the automotive industry.
SEE: Photos: 3D printed dentures, bike, surgical tools, and more (TechRepublic)
The medical industry relies extensively on 3D metal printing, as the ability to print knee and shoulder joint replacements to match the shape of the patient allows the implant to more easily mesh and grow with the bone to create sturdier replacement joints. Dentistry has also been a quick adopter of 3D printing technology, as the shape and placement of teeth varies widely between patients, making one-size-fits-all solutions impractical for that field.
What vendors offer 3D metal printers?
The 3D metal printing industry is not wanting for competition, as a variety of vendors offer 3D metal printers suitable for rapid prototyping and mass production, as well as specialized printers tailored for medical/dental and aerospace applications.
3D Systems is a South Carolina-based company founded by Chuck Hull, the inventor of the first SLA rapid prototyping system. The company has acquired numerous smaller 3D printing technology firms worldwide. 3D Systems offers printers for a variety of materials, including SLA printers to create casting patterns for traditionally manufactured metal parts.
For direct metal printing, 3D Systems offers several models, starting with the DMP Flex 100, with a build volume of 100 x 100 x 80 mm (3.94 x 3.94 x 3.15 in), up to the DMP Factory 500 Solution, with a build volume of 500 mm³ (1.77 ft³). Specialized versions of the DMP Flex 100 and ProX DMP 200 exist for the dental industry, with software purpose built for that use case.
DMG Mori is a machinery company with dual headquarters in Nagoya, Japan and Bielefeld, Germany. The company offers powder bed (DMLS) and powder nozzle 3D printers, the latter of which can be used to print on top of existing parts for customization or repair.
EOS is a German company that sells DMLS printers. The high-end model, EOS M 400-4, features a build volume of 400 mm³ (15.75 in³) with four 400 watt lasers operating independently of each other, with an overlap area of 50 mm.
EOS also offers the Precious M 080 purpose built 3D printer for the jewelry and watchmaking industries. The Precious M 080 is designed to work with precious metals commonly used in those industries.
GE Additive purchased a number of 3D printing companies, which presently operate under their original names. Of these, Concept Laser offers the X Line 2000R, which the company touts as being the largest DMLS printer with an 800 x 400 x 500 mm (31.50 x 15.75 x 19.69 in) build volume.
Arcam, another GE Additive company, offers EBM printers, which the company touts as being able to withstand process temperatures up to 1100 °C, making it possible to use materials that require high process temperatures, including titanium aluminide and Alloy 718.
As an inkjet and laser printer manufacturer, HP is familiar to millions. The company is expanding into the 3D metal printing market with the HP Metal Jet printer, with a 430 x 320 x 200 mm (16.9 x 12.6 x 7.9 in) build volume, using a binder jetting system. HP touts the Metal Jet as being "up to 50x more productive" than other binder jetting and SLM systems. HP is offering pre-orders for the Metal Jet for "less than $399,000."
Stratasys is developing a proprietary printing technology called layered power metallurgy (LPM), which the company claims is intended to address shortcomings in existing 3D metal printing technology. The company also offers FDM and binder jetting 3D printers.
How can I print objects in 3D, without buying a 3D metal printer?
For organizations that lack the production volume to warrant buying a dedicated 3D metal printer, services exist to print and ship your designs to you. These services are useful for organizations seeking to leverage 3D printing for rapid prototype and proof of concept demonstration, without the six-figure upfront cost of a dedicated printer.
HP is offering a 3D metal printing service through production partners using Metal Jet printers, starting in 2019.
Third-party printing services, which are not affiliated with a specific 3D printer manufacturer, offer a diverse range of options and materials.