IMR Materials Testing Technical Blog

UPDATED-The Top 8 Metal Additive Manufacturing Methods

The first 3D printer may have been invented in 1983, but this invention—although revolutionary—didn’t take off right away. This is because the original models were so cost-prohibitive and functionally limited that most manufacturers couldn’t realize a significant enough return on their investment to make the purchase worthwhile. 

Today though, 3D printers are much more affordable and practical than in previous years. Modern 3D printers can bring highly specialized, cost-effective designs to life using a comprehensive list of materials, including a wide variety of metals, plastics, epoxies, and ceramics. Metal-based additive manufacturing is one such process that has advanced significantly in recent years, largely thanks to the expanding presence of 3D printing.

Additive manufacturing uses CAD drawings or other computer-generated blueprints to create sophisticated objects one layer at a time. These ultra-thin layers are measured in microns or micrometers—the thinner the layer, the more accurate the result, and also, the longer the object takes to print. There is usually little need for machining, so additive manufacturing can handle the strictest design specifications without difficulty.

As technology advances, industrial 3D printers are becoming faster and more affordable. 

In turn, manufacturers have finally begun to reap the benefits metal additive manufacturing can offer. Once used only for rapid prototyping, additive manufacturing can now produce incredibly complex finished parts quickly, allowing for larger-scale production of goods that are suitable for end-use.

Some industries, such as the aerospace and medical device industries, have been experimenting with 3D printers to create highly specialized parts and components for several years. We are now seeing the broader custom manufacturing sector turn to additive manufacturing as the standard for difficult design challenges.

METHODS OF ADDITIVE MANUFACTURING

Once a tool used exclusively to create complex designs out of plastic, additive manufacturing methods have now advanced to employ an array of metals and alloys to create fully functioning prototypes and parts. The most common metal 3D printing methods now available include:

Binder Jetting

By combining a powdered material with a liquid binding agent to print objects, binder jet 3D printers print a wide array of items using a vast selection of different material powder and binding agent combinations, including a wide selection of metals.

Material Jetting

This process is a lot like what happens with an inkjet printer for two-dimensional images. With material jetting, certain materials are jetted or dropped through a nozzle onto a build platform layer by layer, and each new layer is cured with ultraviolet light. These materials are deposited in drops, which limits the kind of material that can be used. In this case, polymers, waxes, and similar substances are used because they are viscous and can form droplets.

Directed Energy Deposition (DED)

This method applies a laser or electron beam welder to melt metal into each design layer. Depending on the specific type of printer, this method uses either a metal powder bed or a metal wire as a material source, shaping or forming the material into the desired result. DED is one of the fastest metal additive manufacturing methods available, and the melting/cooling process creates dense, usable end parts. This method is also popular for part repair operations.

Powder Bed Fusion

Powder bed fusion printers employ a laser or electron beam to melt a layer shape into a bed of powder. Additional powder is spread over the top for the creation of a new layer and the process is then repeated. Each layer of melted powder binds together to create a pre-programmed design. This process often uses metals or alloys to build sophisticated working parts. 

Sheet Lamination

Using ultrasonic welding, sheet lamination connects small, thin sheets of material to form specialized designs. Components created through sheet lamination are unique from other 3D-printed objects in that they typically require additional CNC machining before being ready for market.

Direct Metal Laser Sintering (DLS)

By using a laser to heat and form metal powders into complex shapes, this method is one of the most accurate forms of metal 3D printing. Parts printed by direct laser sintering are more durable and affordable than parts created with traditional machining methods; Because of this, they are often employed in the aerospace, oil and gas, or medical device sectors.

Metal Digital Light Processing (DLP) Printing

One of the most recent developments in metal 3D printing, DLP printing involves applying an organic coating to a thin photosensitive metal resin before exposing it to a computer-driven UV projector. The automated projector casts UV light onto the resin in the form of the programmed design; Each layer is formed and dried in this way until the design is completed. The item is then heated in an industrial oven to remove the organic coating material, leaving a smooth and finished final product.

Vat Photopolymerization

Vat photopolymerization starts just as it sounds: With a vat. This vat contains liquid photopolymer resin, and an ultraviolet or UV light cures and hardens the resin according to the design, while a platform moves the object downwards after every new layer cures. Wherever the resin and UV light come into contact with each other, the resin hardens, forming the final design layer by layer. 

BENEFITS OF METAL ADDITIVE MANUFACTURING

As these methods demonstrate, the technology behind additive manufacturing has advanced significantly in the past decade, with different tools and techniques available to achieve different effects, all using different materials for various outcomes. 3D printer capabilities now extend far beyond simple rapid prototyping to offer numerous benefits for manufacturers for mass production, including 

Innovation

For decades, 3D printers have enabled designers to experiment during the prototyping stage. New ideas can be quickly printed and tested, allowing for innovative progress in minutes instead of weeks or months.

Cost Effectiveness

Not only is additive manufacturing equipment more affordable than ever before, but newer machines are also fast and reliable—often comparable or superior to more standard fabrication techniques. With 3D printing, manufacturers can scale production and implement rapid design changes, demonstrating significant ROI.

Easy Education Access

The manufacturing industry is facing a significant shortage of skilled labor, but new educational opportunities can help convert an organization’s workforce into skilled additive manufacturing workers.

Eco-Friendly Efficiency

More energy efficient than large standard or CNC machine tools, additive manufacturing also produces less waste than most machining processes.

MATERIALS TESTING WITH IMR

Additive manufacturing is only as successful as the materials used in the process. IMR Test Labs offers a comprehensive range of testing services to confirm the quality of your raw materials or finished 3D-printed parts and components. We provide extensive testing services to clients in myriad industries around the world to help them guarantee that the materials they work with are of the highest quality, including:

• Powder Analysis

A majority of 3D printers begin with a powdered material. IMR offers full chemical analysis, morphology analysis, percent crystallinity testing, and particle size testing services to verify the purity and quality of your raw materials. Testing your powders prior to fabrication ensures you don’t waste valuable production time creating parts with substandard materials.

• Finished Part Testing

Metal 3D printing relies largely on melting metal materials to bond layers together. Our density tests measure the cohesiveness of the bonds between layers to ensure durability and quality. Tensile, compression, and impact tests analyze the amount of force a finished product can withstand before incurring damage. Fatigue testing is used to determine a components durability over the life of the expected application.

In addition to our labs in Ithaca NY, Louisville, KY, and Portland OR we also have additional certified testing facilities in Singapore and China to make our comprehensive range of testing and analysis services available at multiple points across your supply chain.

To learn more about how IMR Test Labs can help you analyze your additive manufacturing materials, please request a quote or contact us.