June 28, 2022

How Does Metal 3D Printing Work?

When discussing additive manufacturing or layer manufacturing in 2022, 3D technology and metal 3D printing always comes to mind. While metal printing in 3D was still in its infancy just a few short years ago, it’s now one of the fastest-growing and most heavily invested industrial technologies in use today.

In this post, we’ll address some of the most common questions regarding 3D metal manufacturing, including what it is, the advantages of using it, how it works, the technologies behind it, and more.

Metal 3D Printing – What is It?

Metal 3D printing is a general term used to describe several different forms of layering and additive manufacturing technologies. In its simplest form, metal 3D printing involves the use of any technology to create metal components and objects by sintering, melting, and welding metal material layer by layer.

Today, thanks to continued advancements in metal 3D printing technology, certain 3D metal printed objects are just as precise and look just as good as conventional machined parts.

There are several different metal 3D printing technologies available to create a wide variety of 3D printed metal components and objects. While metal printing is primarily used in the aerospace and engineering industries, 3D printing technology is quickly branching out.

Whether they are implemented as sole technologies in the manufacturing of metal components or introduced alongside other technologies into an existing supply chain, metal manufacturing 3D technology continues to evolve and improve.

Why Use Metal 3D Printing?

For the longest time, machining was one of the only methods available for metal manufacturing. While CNC machines are capable of making an almost endless variety of metal components and parts, 3D printing can be used to create an even wider variety of components with greater details and complex shapes.

This is the main advantage of metal 3D printing: it’s nearly limitless in the complex shapes and items it can be used to create. However, these aren’t the only benefits of going 3D. Some additional advantages of metal printing in 3D include:

• Faster manufacturing of complex shapes and details
• Save time and money by 3D printing in assembly line fashion
• Able to create lighter products without sacrificing strength
• More cost-effective than conventional manufacturing methods
• Almost zero material waste depending on the process you use

In other words, printing in 3D works terrifically and is highly recommended for manufacturing intricate, highly detailed metal components and parts. However, its uses are expanding by the day along with advancements in metal 3D printing technology.

Next, let’s take a closer look at exactly how printing metal components in 3D works.

How Does 3D Metal Manufacturing Work?

There are many different methods of metal manufacturing in 3D. While each method and technology has much in common with the next, there are certain differences dictating which materials they can and can’t work with. Here’s a quick overview of the different types of metal 3D printing used today:

Direct Metal Laser Sintering (DMLS)

DMLS is the most common method of 3D metal manufacturing. With this method, a laser is used to sinter alloy powder layer by layer to form an object. The individual layers are created as the laser is pointed at a powder bed and guided by a CAD (computer-aided design) file. Once the creation of one layer is complete, the printer spreads out more powder and the process is repeated. Through this process of layering and repetition, the metal component is created. The digital process eliminates the need for physical moulds and is exemplary in producing high-quality, yet complex metal components. DMLS is used in manufacturing finished mechanical parts, medical instruments and devices, tools, and more.

Selective Laser Melting (SLM)

True to its name, SLM melts material, and the printing takes place in an inert gas chamber. During the process, a laser melts and combines the metallic powders together. Once one layer is completed, a new layer of metallic powder is added and the next print cycle begins. In general, SLM-printed products usually offer increased strength properties as they have few or no voids in their frame. This gives SLM printed products in 3D nearly the exact same parameters as metal-casted products and they are commonly used in the building of complex structures.

Electron Beam Melting (EBM)

EBM is similar to SLM, however, an electron beam is used rather than a laser. In this process, a high-energy beam of electrons melts the powdered metal. The beam produces a jet of electrons, guided by a magnetic field. Layer upon layer of the powdered metal is melted together to create an object with the specifications set out by the CAD software. The process takes place in a vacuum chamber to protect against oxidation that can antagonise highly reactive materials. EBM is faster and even more precise than laser-printing methods and is used in sectors such as aerospace, defence and medicine.

The Future of 3D and Layer Manufacturing

While the technologies above remain prevalent in 3D manufacturing, there are additional technologies such as selective laser sintering (SLS), binder jetting, and laser deposition. Much like the above forms of printing, these further technologies utilise varying materials and have their own unique processes. The 3D printing market is constantly growing and new technologies are allowing for faster metal printing. Supersonic particle deposition (SPD) or cold spray (CS) is a key example of this. Through this process, micron-sized particles of a metal or alloy are accelerated through a spray gun using a heated high-pressure gas such as helium or nitrogen. The particles exit at supersonic velocities and bond with the underlying materials. 

However, unlike other cold spray processes, rather than using heat to melt metal powders, SPEE3D developed ‘Supersonic 3D Deposition’ (SP3D). This is the name given to the patented process in which a rocket nozzle accelerates air up to three times the speed of sound, into which metal powder is injected then deposited onto a substrate maneuvered by a six-axis robotic arm. In this process the sheer kinetic energy of the particles hitting each other causes the powders to bind together to form a high density part with metallurgical properties superior to casting. This means SP3D technology is allowing for metal printing faster than ever before, up to 1000 times faster than more traditional metal additive manufacturing methods.

To Summarise

As explained above, metal 3D printing is a term used to describe varying forms of layering and additive manufacturing technologies. In its simplest form, metal printing in 3D involves the creation of metal components and objects by sintering, melting, and welding metal material layer by layer. Certain differences between each method and technology dictate which materials they can and can’t work with. Direct metal laser sintering (DMLS) uses a laser to sinter alloy powder layer by layer to form an object, whereas selective laser melting (SLM) melts and welds powder particles together. Electron beam melting (EBM) is similar to SLM but an electron beam is used, rather than a laser. Looking to the future of metal 3D printing, technologies such as SPEE3D’s cold spray SP3D technologies are innovating additive manufacturing so that metal parts can be produced faster than ever before.

How We Can Help

To find out about SPEE3D’s products or to just find out more about metal 3D printing, feel free to email us at contact@spee3d.com or call us on +61 (03) 8759 1464.