How Do Metal 3D Printers Work

How do Metal 3D printers work

Metal 3D Printers - Guide to everything in 3D printing with metal - 2020

Metal 3D Printing has become increasingly popular lately. One of the reasons is that metal printing in 3D is by far more cost-effective, resource-efficient and also time-efficient.

Imagine that you can print in all different metal materials (Everything from stainless steel and aluminum to pure iron or precious metals such as gold).

You could create miniatures, statues, jewelery, functional parts, kitchen utensils, prototypes, advanced machine equipment and much more.

3D printed metal objects are, with today's technologies, just as good, if not better, than the traditionally created metal objects.

In traditional manufacturing, you usually get a lot of waste of materials, depending on technology. Of course, different techniques provide different efficiencies, but as an example, it is very often a metal plate used to punch or cut from.

Imagine the amount of leftover material if you have a sheet of 100cm X 100cm size and should cut out circles out of it. Of course, much of it can be recycled, but recycling also takes resources.

What is a metal 3D printer?

3D metal printing is a machine that can create metal objects from design files, usually from a CAD program. There are different types of printers for metals, and they use different techniques. We go through these techniques further down.

These types of 3D printers are usually costly, and at present, nothing a private person usually gives up for home use.

However, some Filaments give the illusion of metal in 3D printing. These metal filaments are plastic, with additions of metals to get a slightly metallic look. You can read more about metal filaments below, where we go through the materials.

what is 3D metal printing used for?

At present, this technology is widely used in industries that have high demands on precision, weight, efficiency and more. For example, it is very difficult to make complex parts traditionally, but with a 3D printer that can handle metal, it becomes easy.

You also use these machines when you want to create optimal 3D printing in metal in terms of weight and structure when you design exactly what you need and no more for it. This way you do not waste material.

Examples of areas that utilize metal 3D printing

  • Medical implants
  • This area is large because usually, every implant is tailor-made, which makes it more efficient with 3D writing.
  • Jewels and jewelery
  • This area is also growing, as you can create nice geometric shapes relatively easily with this technique.
  • Aerospace
  • Here it becomes even more efficient with 3D objects in metal to save time, weight, and complexity.
  • Automotive
  • This is where metal 3D printing begins, also for the same reasons as Aerospace and aviation.

Metal 3D printer for automotive

Advantages and disadvantages of these machines?

Easy to create complex objects.

+ Optimum weight and structure, no waste of material.

+ Time efficient.

- Materials and personnel costs are high with this technology, and simple objects are thus cheaper with traditional technology.

- The build size of metal 3D printers is usually a variable that limits its use.

- Already existing designs and models cannot always be applied to a 3D printer without major modifications, which entails costs and obstacles to moving on to this technology.

How do metal 3d printers work - The Techniques

These 3D printers that print metal objects work according to the same process as the other 3D printers, namely that layers upon layers are built up until you have a finished object. These machines operate according to different processes, which are explained in more detail below.

How SLS Metal 3D Printers Work (DMLS / SLM)

Direct metal laser sintering (DMLS), or selective laser sintering (SLS) / selective laser melting (SLM) is a technology that metal 3D printing use that is becoming more common and probably one of the most common in industries. This method works such that an energy source (laser or another form of a beam) melts and cures a raw material which is usually in powder form (fine-grained round powder particles).

What is the difference between Selective Laser Sintering (SLS) and Selective Laser Melting (SLM)?

SLS 3D printers sinter, that is, they heat the powder sufficiently to achieve a binding effect so that the particles can be sintered together into a mold. SLM melts, that is, it goes even further in the heating until the powder is melted and assumes a whole shape. As you understand, SLS can, therefore, control the porosity of the object.

How Directed Energy Deposit (DED / LMB) Works

DED 3D printing technology (Directed Energy Deposition), also known as Direct Energy Deposition, creates parts by assembling/melting the raw material and building up the 3D model layer by layer.

This method is sometimes also called Laser Metal Deposition (LMB).

These metal 3d printers work by assembling/melting a raw material available in either powder or wire form. Other popular names for DED are "laser engineered net shaping", "directed light fabrication", "direct metal deposition", "Laser Deposition Welding" (LDW) and "3D laser cladding".

The DED technology comes in many different brand names and patents / specific techniques, we go through some common ones below.

LENS, LMD-p are two techniques that use powder as raw material, while EBAM and LMD-w use wire as raw material.

LENS metal 3D printing​

This 3D printing method thus works during the DED process, and functions as it adds a powder as raw material, which is for example metal, alloy, ceramic or composite in the base. The entire printing must be done in a sealed chamber that controls moisture levels, etc. This to have high purity.

EBAM 3D printer for metal

Electron Beam Additive Manufacturing (EBAM) is a technology used primarily to create large structures. This method works by threading the feedstock. The thread is usually 3mm thick and often of titanium. The technology for EBAM is well sophisticated and not all organizations are allowed to use it. It is applied, inter alia, today in military, research, aerospace, oil and sea applications.

EBM 3D printing

Electron beam melting is another technique that can take both powder or wire as raw material. What sets this technique apart from the others is that the raw material is heated utilizing electromagnetism in a vacuum.

Cold Spray Metal 3D Printing

This technique means that particles of metal powder are pushed away with a high-speed gas jet. The particles are fired against a substrate layer and act as a liquid upon impact, through a process known as plastic deformation. After they are met, the particles are quickly cooled to form a metal object or 3D object.

NASA has used this method in space.

Binding Jetting 3D printing technology

Binder Jetting <is the process of binding the powder using a so-called binding agent. The binder is often dropped onto the powder until fully bonded.

The process is used by Exone.

After it is glued together by the binding agent, the object has to be thermally processed to remove the binding agent and thus only a 3D printed metal object remains. Binder Jetting is usually said to be up to several times more cost-effective compared to other 3D printing methods for metal. This method of printing metal 3D objects usually gives the object slightly lower mechanical properties compared to SLS / SLM and the others. It is also very difficult to get detailed items with this method.

What materials or metals are used?

The materials or metals that can be used depending on the type of technology the 3D printer utilizes or works on. There are many different metals to use, and metals have many properties that are important, especially for industrial productions, where exact requirements are set for parameters such as strength, elongation, tensile, fracture elongation, fatigue limit, density to name a few.

We go through the most common materials/metals for 3D printers below.

Titanium

Pure titanium (Ti64 or TiAl4V) is one of the most common materials for 3D metal printers. This is because Titan has high strength and lightness, making it versatile to be used in many applications. Titanium is also corrosion-free, which means that this metal becomes even more advantageous. It also does not expand as much as many other metals at high heat. This material comes in powder form which makes it work with most common metal 3D printers but also works with the Binder Jetting method.

This material is mainly used in medicine, aerospace, automotive and engineering. One disadvantage, however, is that this material can explode, which is why Titanium is printed in a vacuum chamber or argon gas atmosphere.

Stainless steel

Stainless steel is one of the most affordable materials for metal 3D printing. It can be used in many different applications as it is very strong. Stainless steel is very popular in industries, as it contains cobalt and nickel, which gives it somewhat elastic properties as well.

Inconel

Inconel is a metal that has very good corrosion properties. The metal is mainly made of nickel and chromium and can withstand extremely high temperatures (up to 1200 degrees C), which makes this material widely used in oil and chemistry, as well as the space industry.

Aluminum

Because of its ease, aluminum is a very popular metal for 3D printers. Generally speaking, aluminum is a strong and light material with good heat properties. Aluminum is also electrically conductive, giving it many applications. It is often printed with DMLS printers. As you know, aluminum is used in principle everywhere in the industry.

Cobalt Chrome

This metal is often used to 3D print turbines, implants and orthopedic products, and more. This is because the metal has very high strength. This material is very stress-resistant and can withstand wear even under high temperatures.

Copper and Bronze

These metals are more widely used in a design, sculpture, models, and artistic objects. The metals are too expensive and have too poor properties for use in the industry.

Precious Metals / Gold, Silver

These types of metals are mainly used for jewelry and jewelery. Most 3D printers that use powder raw materials for metal printing can also print with these precious metals.

Metal filament for regular 3D printers

You can also print 3D objects from your regular FFF (FDM) 3D printers <which have elements of metal, namely with metal filaments.

These filaments are plastic with additives of different metals, to give a look, weight, and feel of metal on 3D printing.

Most often there is a ratio of 50% plastic and 50% metal in these filaments, but there are also filament manufacturers who claim that they have a ratio of 85% metal and 15% plastic.

Metal filaments are thus melted in the 3D printer's nozzle, just like plastic filaments, while the object is built up layer by layer.

It is worth mentioning that these types of filaments also wear on the nozzle and may require slightly stronger components in your home printer's 3D printer.

Some common brands are ColorFabb, ProtoPasta and TreeD Filaments, which sell these types of filaments.

Can a 3d printer print metal objects? Customize your "regular" 3D printer to print in metal

Can you print in metal with your usual 3D printer?

It's a question we often get.

To customize your home-use 3D printer to print in metal does not require much.

If you read the previous paragraph you know that no filament is pure metal, but it is plastic that contains metal.

Make sure you have an existing FFF (FDM) 3D printer at home, which takes regular filaments as raw material.

No heated building plate is required either, which means that even the cheapest 3D machines could print in metal.

The first thing to do is to upgrade your nozzle, as metal filaments wear on nozzles quite well. It is therefore good to buy one that is made of strong metal (ironically).

Maybe you should have a couple in reserve as well.

Another important thing is that you should finish the 3D printing to get the look you want. This does not require much effort, but it may suffice with a brush, blasting, waxing or the like. All filaments have different methods, which are usually described by the manufacturer.

There are a lot of resources about this on the internet.

You need to set the settings on the 3D printer according to the manufacturer's instructions for the particular metal filament you purchased. Then you probably need to experiment until you get the correct settings on all parameters. It is often required a couple of times before it gets good!

Printing services in metal

There are hundreds of companies offering 3D printer services that can print in metals, but we have compiled a list of the most popular services to make it as easy as possible for you.

All3DP

At All3Dp you can compare prices of all services that are connected, and thus get a preliminary indication of how much it would cost to print the model. You upload your model and can choose from different metal materials, as well as receive shipping costs directly.

Shapeways

Shapeways is one of the most popular 3D printing services on the Internet, offering two services: one for single objects and one for industrial rapid prototyping with industrial EOS or similar 3D printer. Choose from different metals, such as aluminum, brass, bronze, gold, platinum, steel, silver and precious metals. There is also wax.

Sculpteo

Like Shapeways, Sculpteo is a 3D printing service that offers uploading models to get quotes on-line. Sculpteo also offers to open an online store to offer its products. Their 3D machines include EOS, 3D Systems, Stratasys and ZCorp. The materials they offer are mostly aluminum, brass, and silver.

i.materialise

Like the above services, i.materialise also offers 3D printing of metal for both individuals and companies. After the item has been printed, through a special gallery you can offer your product for sale. Metals that can be selected include aluminum, brass, bronze, gold, platinum, steel, titanium, silver and precious metals.

3DHubs

Through 3Dhub's platform, you can search and connect with nearby 3D writing services directly. Upload your STL file and get an estimate on price instantly. You can easily filter by rating, distance, materials and more to search for a service. No matter what, it is very likely that someone or someone near you can print your item. If you mark the search with "HD", you also get industrial-quality services that can print in metals of various kinds.